JPH0440478B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a polyvinyl ester resin containing any one type of specific cationic group (hereinafter cationized).
For example, by adding PVAc-based resin (abbreviated as PVAc-based resin) to the pipe dispersion, it has excellent dry paper strength.
The present invention relates to providing paper having advantages such as a high filler yield rate. When producing normal paper, cellulose fibers are dispersed in water to prepare a pipe slurry, to which sizing agents, pigments, dyes, paper strength enhancers, etc. are added, and then aluminum sulfate is added and the above-mentioned additions are made. After the agent is fixed on the pulp, paper is manufactured through a papermaking process. The paper obtained in this way has many drawbacks due to the acidity caused by aluminum sulfate, such as a decrease in strength of the paper over time, discoloration, corrosion of the metal when it comes into contact with metal, and a decrease in printability. It is something. In addition, water-soluble polymers such as polyvinyl alcohol, polyacrylamide, and starch are used to increase the strength of paper, but these water-soluble polymers have a low fixation rate on paper, and therefore are difficult to fix on paper during the papermaking process. Since the internal addition method in which it is added before formation cannot fully exhibit its effect, it is necessary to process it by dipping or coating after forming the paper web. However, as a result of intensive studies to solve these problems, the present inventors added a polyvinyl ester resin (cationized PVAc resin) containing one type of specific cationic group to the pulp dispersion. The inventors have discovered that paper with excellent performance can be obtained by manufacturing paper using the same method, and have completed the present invention. According to the present invention, the following remarkable effects can be obtained. Because the monocationic PVAc resin has excellent fixing properties to pipes, the dry paper strength of the paper increases. 2 Therefore, treatment with a paper strength enhancer after paper web formation is unnecessary, resulting in a large economic effect. 3. Good yield of fine fibers and filler,
The clarity of water and white water is improved, and workability and wastewater treatment are greatly improved. Even in the so-called acid size of the rosin/aluminum sulfate system, the amount of aluminum sulfate can be reduced, so the various drawbacks that occur when aluminum sulfate is used are alleviated. 5. In the case of neutral size, the above 1),
In addition to the effects 2) and 3), the various drawbacks caused by aluminum sulfate are completely eliminated. The cationized PVAc resin in the present invention has the general formula It is a polyvinyl resin containing a cation group represented by the formula, where R ₁ is alkylene or hydroxyalkylene, R ₂ , R ₃ , and R ₄ are alkyl, and when X is an inorganic or organic anion, it is a halogen-substituted alkyltrialkyl. Obtained by reacetylation of the reaction product of ammonium chloride and polyvinyl alcohol (PVA). Examples of the ammonium chloride include 3-chloro-2-hydroxypropyltrimethylammonium chloride, 2-chloroethyltrimethylammonium chloride, 3-chloropropyltrimethylammonium chloride,
Examples include 2-chloro-2-hydroxyethyltrimethylammonium chloride. PVA
The reaction between PVA and the ammonium chloride proceeds through a dehydrohalogenation reaction between the hydroxyl group in PVA and the halogen bonded to the alkyl group in ammonium chloride. It will be introduced inside. Furthermore, during re-acetylation, it is necessary to ensure that there are no hydroxyl groups remaining in the resin. In the formula, when R ₁ is alkylene or hydroxyalkylene, R ₂ is hydrogen, R ₃ and R ₄ are alkyl groups, and X is an inorganic or organic anion, 2-chloroethyldimethylamine, 3- Chloro-2-hydroxypropyl dimethylamine and the like are used for this purpose in the form of an inorganic acid or an organic acid salt of a reacetate of a reaction product with polyvinyl alcohol. The polyvinyl ester resin containing the cationic group (a) can be obtained by reacetylation of the reaction product of ammonium chloride, amine, etc. and PVA as described above, but the production method will be exemplified in more detail. First, PVA is made into a slurry with an alcohol solvent, an alkali catalyst is added, and the reaction is carried out at 30 to 50°C for a certain period of time to replace the hydrogen in the hydroxyl group of PVA with metal (alcoholate reaction). Next, a compound having a cationic group such as the halogen-substituted alkyltrialkylammonium chloride or 2-chloroethyldimethylamine is added and reacted at 40 to 50°C for a certain period of time (sthionation reaction). An acetylation solution (acetic anhydride/pyridine/acetic acid mixture) is added to the obtained cationized PVA and reacted at 90 to 100°C for a certain period of time to obtain the desired cationized PVAc-based resin. General formula for cationic group (b) (However, in the formula, R ₂ and R ₅ are hydrogen or alkyl, R ₃ and
R ₄ is alkyl, X is an inorganic or organic anion, n
Among polyvinyl ester resins having a cationic group represented by = 1 to 10), when R ₂ , R ₃ , and R ₄ are all alkyl groups, alkenyl trialkylammonium chloride and vinyl ester, especially vinyl acetate, are used. Obtained by copolymerization. Examples of the alkenyltrialkylammonium chloride include allyltrimethylammonium chloride, methalyltrimethylammonium chloride, and 3-butenyltrimethylammonium chloride. Also in the formula R ₂
is hydrogen, and when R ₄ and R ₄ are alkyl groups, it is used in the form of an inorganic or organic acid salt of a copolymer obtained by copolymerizing dimethylallylamine, dimethylmethallylamine, etc. with vinyl ester, especially vinyl acetate. It will be done. General formula as cationic group (c) (However, in the formula, R ₂ and R ₅ are hydrogen or alkyl, R ₃ is alkyl, and X is an inorganic anion.) Among polyvinyl ester resins having a cationic group,
When R ₂ and R ₃ are alkyl groups, they can be obtained by copolymerizing such dialkyl diallylammonium chloride and vinyl ester, especially vinyl acetate. Examples of the dialkyldiallylammonium chloride include dimethyldiallylammonium chloride, diethyldiallylammonium chloride, and the like. During the copolymerization reaction, the diallyl portion undergoes a ring-closing reaction to form the structure shown by formula (c). In the formula, when R ₂ is hydrogen and R ₃ is an alkyl group,
It is used in the form of an inorganic or organic acid salt of a copolymer obtained by copolymerizing ethyl diallylamine, methyl diallylamine, etc., and vinyl ester, especially vinyl acetate. Further, when copolymerizing the above compound with a vinyl ester (typically vinyl acetate, vinyl propionate, etc.), a small amount of other copolymerizable monomers may be used in addition to the vinyl ester. The method for producing the cationic PVAc type resin containing the cationic groups represented by the above general formulas (b) and (c) can be carried out by any of bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, but solution polymerization is usually used. will be implemented. Vinyl acetate and the above cation group in a lower alcohol solvent
Add the compound having (b) or (c), add a polymerization initiator such as azobisisobutyronitrile or benzoyl peroxide, and then react at a polymerization reaction temperature usually in the range of 50°C to boiling point, and then Examples of methods include adding the remaining cationic group-containing compound as appropriate and reacting. Among the polyvinyl ester resins (cationized PVAc resins) containing any one type of cationic group represented by the general formulas (a), (b), and (c) in the present invention,
The cationized PVAc resin represented by the general formula (a) is
As mentioned above, harsh conditions are required for the reaction, and the amount of cationic groups introduced is limited and small. On the other hand, cationized PVAc resins containing cationic groups represented by general formulas (b) and (c) are obtained by copolymerizing vinyl esters, especially vinyl acetate, with specific monomers, as described above. Therefore, it is possible to easily introduce a large amount of cationic groups. Therefore, the cationization represented by general formula (a)
Cationized PVAc resins containing cationic groups represented by formulas (b) and (c) are more suitable than PVAc resins, and their use is desired. The cationic group content of the cationized PVAc resin used in the present invention is suitably in the range of 1 to 20 mol%, preferably 2 to 10 mol%. If the cationic group content is less than 1 mol%, the above-mentioned effects will be poor and the paper will be insoluble in water, while if it exceeds 20 mol%, the resulting paper will tend to have high hygroscopicity, which is not preferred. When using cationized PVAc-based resins, there is no need to particularly adjust the pulp slurry in the case of quaternized ones containing cationic groups represented by general formulas (a), (b), and (c). , can be used in the entire PH range. On the other hand, in the form of an inorganic or organic acid salt of a tertiary amine, the pulp slurry is adjusted to PH6 or less with an acid or a salt, and the tertiary amine is used in the form of an inorganic or organic acid salt. It is preferable to add the cationized PVAc resin to the pulp slurry before the papermaking process, but it can also be added after the papermaking process by dipping, spraying, coating, or the like. Also cationic PVAc to paper
The adsorption amount of the system resin varies depending on the type of paper, the type of cation group, the amount of cation group, etc., but it is usually about 0.1 as a resin content per weight of dry paper obtained.
A sufficient increase in dry paper strength is observed in the range of about 5% by weight. In the present invention, known sizing agents, pigments, paints, paper strength enhancers, etc. used in paper production can be used. Next, the present invention will be specifically explained with reference to Examples. In the examples, "parts" and "%" are based on weight unless otherwise specified. Example 1 100 g of polyvinyl alcohol (average polymerization degree 1800, saponification degree 98 mol%) powder and 400 g of isopropyl alcohol were placed in a flask equipped with a stirrer, the temperature was raised to 40°C, and while stirring, 75 g of 20% sodium hydroxide aqueous solution was added. After addition, the mixture was stirred for 4 hours. The obtained slurry was separated into solid and liquid, and the powder and 3-
85.3 g of chloro-2-hydroxypropyltrimethylammonium chloride was added using a kneader.
The mixture was stirred at 50°C for 7 hours, washed with methanol, and dried to obtain a powder. Add acetylation liquid (10 parts of acetic anhydride to 10 parts of the powder)
1 part of pyridine, and 10 parts of acetic acid) were added at a ratio of 150 parts, stirred at 90°C for 12 hours, and the resulting paste was washed according to a conventional method. The amount of cationic groups (expressed in mol%) was 3.2 mol% of cationized PVAc. A 1% aqueous solution of such cationized PVAc was prepared (resin solution-A), and subsequent experiments were conducted. A predetermined amount of resin solution A- was added to a 3% dispersion of Canadian Freeness 420 c.c. bleached kraft pulp. Paper was made using the TAPPI standard paper making method without adding aluminum sulfate and the pH remained at ^7.1 .
After press treatment for 5 minutes and drying at 105℃±5℃ for 5 minutes, the resulting paper was heated at 20℃×65%RH for 24 hours.
Adjust the paper with a basis weight of 80 g/m ² after leaving it for a while, use it to determine the fixation rate of cationized PVAc resin, measure the specific rupture degree by Müllen's burst test, and measure the tearing length by Schottsper tensile test. Measured by machine. Also
IGT strength was measured using an IGT printability tester. The results are summarized in Table 1. Example 2 A flask equipped with a stirrer was charged with 500 g of vinyl acetate, 75 g of methanol, and 1.4 g of allyltrimethylammonium chloride, and the system was purged with nitrogen while stirring, and the temperature was raised to 60°C. After adding 52g of 3.5% methanol solution of azobisisobutyronitrile as a polymerization initiator, 5.2g of allyltrimethylammonium chloride and methanol were added over a period of 5 hours and 20 minutes.
57 g was added dropwise accordingly. After the polymerization reaction was completed, methanol vapor was blown into the reaction solution under reduced pressure to drive out unreacted vinyl acetate monomer to obtain cationized PVAc with a degree of cationization of 2 mol%, and a 1% solution of this was prepared ( Resin liquid-B). In Example 1, resin liquid-A was replaced with resin liquid-A.
Paper was obtained in the same manner except that B was used, and the fixation rate of the resin to the paper, specific rupture degree, tearing length, and I.
GT strength was determined. The results are summarized in Table 1. Example 3 According to Example 2, vinyl acetate and dimethyldiallylammonium chloride were copolymerized to obtain cationized PVAc with a degree of cationization of 7.3 mol %, and a 1% solution of this was prepared (resin liquid-C). Using this, paper was obtained in the same manner as in Example 1, and various properties of this paper were determined and listed in Table 1. Example 4 According to Example 2, vinyl acetate, dimethyldiallylammonium chloride, and N-acrylamidoethytrimethylammonium chloride were copolymerized to give a cationization degree of 4.2 mol%.
PVAc was obtained and a 1% solution thereof was prepared (resin solution-D). Using this, paper was obtained in the same manner as in Example 1, and various properties of the paper were determined and listed in Table 1. Comparative Examples 1 to 2 In Comparative Example 1, when cationized PVAc is not used,
Comparative Example 2 is a case where polyvinyl alcohol having a degree of polymerization of 1800 and a degree of saponification of 98 mol% is used. Examples 5 to 9 According to Example 2, Example 5 used a PVAc resin containing 3.8 mol% of 2-chloroethyldimethylamine, and Example 6 used a PVAc resin containing 2.3 mol% of dimethylalamine. In step 7, a PVAc resin containing 3.4 mol% of ethyl diallylamine was obtained,
Each resin liquid was prepared. Before adding this to the pulp slurry, the pH of the pipe slurry was adjusted to 4.5 with aluminum sulfate, and then a predetermined amount of each resin liquid was added to obtain paper in the same manner as in Example 1. Various properties of the paper were determined and listed in Table 1. In Example 8, the pH of the pulp slurry in Example 1 was adjusted to 4.5 with aluminum sulfate, and in Example 9, the pH of the pipe slurry in Example 2 was adjusted to 4.5.
This is when the pH was adjusted to 4.5 with aluminum sulfate. Other paper was obtained in the same manner, and various properties of the paper were determined and listed in Table 1. Comparative Examples 3 to 4 In Comparative Example 3, the pipe slurry in Comparative Example 1 was
When the PH was set to 4.5, Comparative Example 4 corresponds to the case where the pipe slurry PH was set to 4.5 in Comparative Example 2. Examples 10 to 12 In Example 10, 0.5 part of a rosin-based sizing agent (based on pulp) was added to the pipe slurry in Example 1, in Example 11 to the pipe slurry in Example 2, and in Example 12 to the pipe slurry in Example 7. 100
), 25 parts of talc (based on 100 parts of pulp) were added, the pulp slurry pH was 4.5, and paper was made in the same manner as in Example 1, and the Steckigt sizing degree and talc fixation rate were determined and shown in Table 2. Described.

【table】

[Table] Example 13 A reaction product of 3-chloro-2-hydroxypropyltrimethylammonium chloride and polyvinyl alcohol (average degree of polymerization 1700, degree of saponification 99 mol%) was reacetylated in the same manner as in Example 1. 1 of cationized PVAc with a degree of cationization of 3.2 mol%
% solution was prepared. 70 parts of beaten pulp and 30 parts of waste paper are dispersed and stirred in water.
Add 100 parts of the above resin liquid (1 part resin/100 parts pulp) to this, and leave the slurry PH as it is (PH
= 7.1), water was added to make the total volume 5000 parts. This slurry is processed into a wet paper machine with a moisture content of approximately 60.
% wet mat was made into paper, which was pressed under a gauge pressure of 1 kg/cm ² and dried by heating in a hot press at 160° C. for 3 hours to produce cardboard with a thickness of 12 mm. Various properties of the obtained cardboard are listed in Table 3. Example 14 Using the resin liquid B of Example 2, cardboard was prepared in the same manner as in Example 13, and its various properties were measured. The results are listed in Table 3. Example 15 Using the resin liquid-C of Example 3, cardboard was prepared in the same manner as in Example 13, and its various properties were measured. The results are listed in Table 3.

【table】

Claims (1)

[Claims] 1. When manufacturing paper, the following general formula (n=1~10) (However, in the formula, R ₁ is alkylene or hydroxyalkylene, R ₂ and R ₅ are hydrogen or alkyl, R ₃ and R ₄
is alkyl and X is an anion).
A method for producing paper, characterized in that it uses a polyvinyl ester resin containing cationic groups.