JP4224746B2 - Paper sizing agent - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper sizing agent, which is effective not only for normal acidic sizing, but also for neutral sizing without using a sulfuric acid band or alkaline sizing using calcium carbonate as a filler, with a rosin-bonded cationic polymer as a main component. To provide a size effect.
[0002]
BACKGROUND OF THE INVENTION
Neutral papermaking has better paper strength retention than acidic papermaking, can extend the use time of felt and wire for papermaking, improve web drainage, improve formation, There is an advantage that paper quality is improved.
In addition, unlike the case of acid papermaking, there are few problems of paper deterioration and wastewater regulation, which is advantageous in terms of water recycling.
[0003]
[Prior art]
As a prior art of a sizing agent effective for neutral papermaking, U.S. Pat. No. 2,964,445 (prior art 1) includes a styrene homolog and acrylic acid or methacrylic acid (hereinafter referred to as acrylic acid and methacrylic acid). A cationic sizing agent obtained by quaternizing a copolymer of an aminoalkyl ester of (meth) acrylic acid) with an alkyl halide is disclosed. Japanese Laid-Open Patent Publication No. 48-11407 (Prior Art 2) discloses a copolymer obtained by quaternizing the above copolymer with epihalohydrin instead of alkyl halide.
[0004]
Further, JP-A-3-16797 (Prior Art 3) discloses that, in an electrophotographic transfer paper containing a sizing agent and a calcium carbonate filler, the sizing agent comprises styrenes and an aminoalkyl of (meth) acrylic acid. Water dispersibility with an ester (or a quaternary salt thereof) as a constituent monomer, or with styrenes and an aminoacrylamide of (meth) acrylic acid (or a quaternary salt thereof) as constituent monomers What is a water-soluble copolymer is disclosed.
Since the sizing agents of the above prior arts 1 to 3 are cationic, they exhibit self-fixing on an anionic charging pulp fiber without using a fixing agent such as a sulfuric acid band, so-called neutrality. Sizing or alkali sizing is possible.
[0005]
[Problems to be solved by the invention]
However, the sizing agents of the above prior arts 1 to 3 are basically quaternized products of copolymers of styrenes and aminoalkyl esters of (meth) acrylic acid or aminoacrylamide, and are also described in the test examples described later. As you can see, in practice, there is much room for improvement in the fixability to pulp fibers and water repellency after fixing in alkali sizing or neutral sizing using calcium carbonate as a filler, and a sufficient size effect is achieved. I can't expect.
[0006]
The present invention is a cationic copolymer-based paper sizing agent containing styrenes and aminoalkyl esters of (meth) acrylic acid as constituent monomer components, and an excellent size effect by neutral sizing or alkali sizing. The development of a sizing agent that indicates
[0007]
[Means for Solving the Problems]
When copolymerizing styrenes and aminoalkyl esters of (meth) acrylic acid, the present inventors co-polymerized these three components in the presence of rosin esters or reinforced rosin esters for both monomers. When polymerized and subjected to quaternization treatment, a very stable water-soluble copolymer is obtained, and the water-soluble copolymer is easily self-fixed to pulp fibers regardless of the presence or absence of a sulfuric acid band, The present inventors have found that the size effect is also superior to that of the above prior art sizing agents, thus completing the present invention.
[0008]
That is, the present invention 1 includes (A) rosin esters obtained by reacting rosins with polyhydric alcohols, and reinforced rosin esters obtained by reacting rosins with polyhydric alcohols and α, β-unsaturated carboxylic acids. In the presence of at least one rosin resin selected from the group consisting of:
(B) styrenes,
(C) For papermaking comprising a water-dispersible or water-soluble rosin-bonded cationic polymer obtained by copolymerization reaction with an aminoalkyl ester of acrylic acid or methacrylic acid and cationized with a quaternizing agent or acid as an active ingredient It is a sizing agent.
[0009]
The present invention 2 is a sizing agent for papermaking, wherein amino acrylamide of acrylic acid or methacrylic acid is used in place of the aminoalkyl ester of acrylic acid or methacrylic acid of (C) of the present invention 1 described above.
[0010]
The present invention 3 is characterized in that, in the present invention 1 or 2, the mixing ratio of the rosin resin of (A) to both the styrenes of (B) and the aminoalkyl ester or aminoacrylamide of (C) is 0.1. A sizing agent for papermaking, characterized in that it is ˜15.0% by weight.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The sizing agent for papermaking of the present invention 1 is a reaction of styrenes with an aminoalkyl ester of (meth) acrylic acid in the presence of at least one rosin resin selected from the group consisting of rosin esters and reinforced rosin esters. It is produced by copolymerizing a functional monomer.
Therefore, the rosin-based resin may be a rosin ester or a reinforced rosin ester, or may be used in combination.
The said rosin ester means what manufactured the rosins and polyhydric alcohol by the well-known esterification method. As the conditions for the esterification reaction, the charging ratio of rosins and polyhydric alcohol is about COOH / OH = 1 / 0.2 to 1.2 in terms of hydroxyl group equivalent ratio of alcohol to carboxyl group equivalent of rosin, reaction temperature Is suitably about 150 to 300 ° C., and the reaction time is about 2 to 30 hours.
The rosins may be tall oil rosin, gum rosin, or wood rosin, which can be used alone or in combination, and includes a disproportionated rosin, a polymerized rosin, a hydrogenated rosin, or other chemically modified rosins.
Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, neopentyl glycol, trimethylene glycol, tetramethylene glycol, dihydric alcohols such as 1,3-butanediol and 1,6-hexanediol, glycerin, trimethylolpropane, Trivalent alcohols such as trimethylolethane and triethylolethane, tetrahydric alcohols such as pentaerythritol and dipentaerythritol, or triethanolamine, tripropanolamine, triisopropanolamine, N-isobutyldiethanolamine, N-normalbutyldiethanolamine Amino alcohols such as can be used alone or in combination.
[0012]
The reinforced rosin esters are obtained by reacting rosins with polyhydric alcohols and α, β-unsaturated carboxylic acids sequentially or simultaneously.
Examples of the α, β-unsaturated carboxylic acids include α, β-unsaturated carboxylic acids or acid anhydrides thereof, fumaric acid, (anhydrous) maleic acid, itaconic acid, (anhydrous) citraconic acid, acrylic acid, Examples include methacrylic acid.
The esterification reaction with the polyhydric alcohol is carried out by the above-mentioned known method.
Further, the strengthening reaction with α, β-unsaturated carboxylic acids is also carried out by a known method. For example, when reacting rosin with α, β-unsaturated carboxylic acids, the reaction temperature is about 150 to 300 ° C. The time is about 1 to 24 hours. The charging amount of α, β-unsaturated carboxylic acids is about 20 parts by weight or less of α, β-unsaturated carboxylic acids with respect to 100 parts by weight of rosins.
When α, β-unsaturated carboxylic acids are reacted after esterification of rosins at a high temperature, rosins having a levopimar skeleton are reduced and isomerized to a dehydroabietic acid skeleton, and the reaction proceeds. Be careful because it may be difficult to do. Conversely, when a rosin and an α, β-unsaturated carboxylic acid are reacted in advance and then subjected to an esterification reaction at a high temperature, a polymer condensate having a large molecular weight is likely to be produced. is necessary.
[0013]
Examples of the styrenes include styrene, α-methylstyrene, vinyl toluene, and p-chlorostyrene.
Examples of the aminoalkyl ester of (meth) acrylic acid include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, 3-dimethylamino-2-hydroxypropyl acrylate, and 3-dimethylamino-2-hydroxy. And propyl methacrylate.
[0014]
The production method of the paper sizing agent of the present invention 1 is not particularly limited, but generally, styrenes as hydrophobic monomers and aminoalkyl esters of (meth) acrylic acid as hydrophilic monomers are rosin-based. In the presence of the resin, radical copolymerization is performed using an initiator such as azoisobutyronitrile in an organic solvent such as benzene or isopropyl alcohol, and after removing the solvent, water is added and the copolymer 3 A secondary amino group is cationized by a conventional method to produce an aqueous solution or dispersion of a rosin-bonded cationic polymer.
As shown in Invention 3, the mixing ratio of the rosin resin to both the styrenes and the aminoalkyl ester of (meth) acrylic acid is preferably 0.1 to 15.0% by weight. When the amount is less than 0.1% by weight, the function of the bulky hydrophobic component due to the rosin resin is reduced and the size effect is reduced. On the other hand, when the amount exceeds 15.0% by weight, the bulky hydrophobic part is strengthened. The chemical stability of the aqueous solution or dispersion of rosin-bonded polymer may be slightly affected.
The sizing agent for papermaking of the present invention 2 uses aminoacrylamide of (meth) acrylic acid instead of the aminoalkyl ester of (meth) acrylic acid of the present invention 1 described above. Accordingly, the production method thereof is basically the same as that of the sizing agent of the present invention 1.
Examples of the aminoacrylamide of (meth) acrylic acid include dimethylaminoethylacrylamide, dimethylaminoethylmethacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylmethacrylamide and the like.
In the polymerization reaction for obtaining the rosin-bonded polymer, an acrylic acid alkyl ester, a methacrylic acid alkyl ester, or the like may be added as a monomer other than the constituent monomers. As the alkyl ester of this (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, Examples include 2-hydroxyethyl (meth) acrylate.
The rosin-bonded polymer is cationized by a quaternizing agent. Quaternizing agents include epihalohydrins such as epichlorohydrin, dihalohydrins, methyl chloride, alkyl halides such as ethyl chloride, ethyl bromide, butyl bromide, aromatic halides such as benzyl chloride, dihaloethylene, propylene oxide, dimethyl sulfate, diethyl sulfate Etc. Further, in place of the quaternizing agent, it may be cationized with an inorganic acid such as hydrochloric acid or sulfuric acid, or a carboxylic acid such as acetic acid or propionic acid, or an organic acid such as sulfonic acid.
[0015]
The paper sizing agent of the present invention has excellent chemical stability, no foaming property, not only acidic sizing in the presence of a sulfate band, but also neutral sizing in the absence of a sulfate band, or carbonic acid. Alkaline sizing using calcium as a filler is also extremely effective.
Therefore, although the sizing agent of the present invention is based on an internally added sizing agent, it has good compatibility with coating agents such as polyvinyl alcohol and oxidized starch, so that it is of course suitable as a surface sizing agent. is there.
The sizing agent of the present invention functions as a self-fixing cationic sizing agent, but may be used in combination with a known rosin-based sizing agent, a reactive sizing agent, or a known cationic polymer such as cationic starch. it can.
[0016]
[Action]
When copolymerizing styrenes and aminoalkyl esters of (meth) acrylic acid, if a rosin resin composed of rosin esters and / or reinforced rosin esters (hereinafter referred to as (reinforced) rosin esters) is allowed to coexist, It can be presumed that the radical addition reaction to the rosin resin proceeds, including the case where the termination reaction of the above becomes a radical addition reaction to the rosin resin.
Therefore, the reaction product of the present invention is a polymer in which a bulky rosin ring is organically bonded, and a copolymer having only styrene and (meth) acrylic acid aminoalkyl ester as constituent monomer components is effective. It is chemically and physically different from the sizing agents of the prior arts 1 to 3 described above as components.
That is, the bond of the rosin ring imparts an appropriate molecular weight as a sizing agent to the polymer and improves the water dispersibility or water solubility of the polymer. Since this rosin-bonded polymer is a cationic polymer, it functions to self-fix to anion-charged fiber pulp, but after fixing to pulp fiber, the bulky hydrophobic component of the rosin ring has a good size effect It is thought that it demonstrates.
[0017]
In this case, the (strengthened) rosin ester used as the rosin-based resin has a rosin ring bonded to each of a plurality of hydroxyl groups of the polyhydric alcohol, and the bulkiness of the rosin lump is improved by weight. Or, it contributes to further enhancement of the hydrophobicity and can be expected to improve the size effect.
Actually, as shown in the test examples described later, the size effect is superior to the sizing agents of the prior arts 1 to 3 described above. For example, in alkaline sizing containing calcium carbonate as a filler, Although the sizing agent does not have a chemical relationship with calcium carbonate, as described above, the sizing agent of the present invention has a rosin ring organically bonded to the polymer. It is considered that the reaction with calcium carbonate occurs and the fixation to the fiber pulp by N cations in the molecule is further promoted as water insolubilization occurs.
Such a function is the same when aminomethacrylamide of (meth) acrylic acid is used instead of aminoalkyl ester of (meth) acrylic acid.
[0018]
【The invention's effect】
As shown in the test examples described below, the sizing agent of prior arts 1 to 3 which is a copolymer only having styrenes and aminoalkyl esters of (meth) acrylic acid as constituent monomer components provides a sufficient size effect. In contrast, the paper sizing agent of the present invention is a rosin obtained by reacting styrenes and aminoalkyl esters of (meth) acrylic acid as constituent monomer components in the presence of (reinforced) rosin ester. Since it is a bonded cationic polymer, the size effect can be exhibited at a high level.
In addition, not only acidic sizing using a normal sulfuric acid band as a fixing agent, but also neutral sizing in the absence of a sulfuric acid band or alkaline sizing using calcium carbonate as a filler can exhibit an excellent size effect.
[0019]
【Example】
Hereinafter, the manufacture example of the sizing agent for papermaking of this invention and the sizing test example of the papermaking containing the said sizing agent in presence of calcium carbonate are demonstrated one by one.
In the following examples and test examples, “parts” and “%” refer to “parts by weight” and “% by weight” unless otherwise specified.
It should be noted that the present invention is not limited to the following examples and test examples, and can be arbitrarily modified within the scope of the technical idea of the present invention.
[0020]
In Examples 1 to 7 below, Example 1 is an example in which rosin ester, aminoalkyl ester of methacrylic acid and styrene are reacted, Example 2 is an example in which rosin is replaced with reinforced rosin ester based on Example 1, Example 3 is an alternative to the quaternizing agent based on Example 1, Example 4 is an example in which a reinforced rosin ester, an aminoalkyl ester of acrylic acid and styrene are reacted, and Example 5 is based on Example 4. Example 6 using aminoalkyl ester of methacrylic acid as Example, Example 6 using Example 4 based on aminoacrylamide of acrylic acid, Example 7 Example of adding acrylic acid ester based on Example 4 It is.
Moreover, Comparative Examples 1-2 are blank examples of rosin-based resins, and are based on the prior arts 1-3 described above.
[0021]
Example 1
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, 20 g of rosin ester (glycerin esterification rate: OH / COOH = 0.5), 70 g of styrene, N, N-dimethylaminoethyl methacrylate 24 g and 70 g of isopropyl alcohol were charged, and the mixture was heated to the reflux temperature and dissolved. Next, from a dropping funnel, a solution of 2 g of azoisobutyronitrile in 30 g of isopropyl alcohol was dropped into the reaction system over 1 hour, and further maintained at the same temperature for 5 hours to complete the reaction.
Next, 70 g of isopropyl alcohol was distilled off from the resulting reaction solution, and 9 g of acetic acid and 100 g of water were added dropwise to dissolve. Thereafter, 380 g of water and 14 g of epichlorohydrin were added, and a reaction was carried out at 80 to 85 ° C. for 3 hours to obtain a papermaking sizing agent comprising a rosin-bonded cationic polymer.
[0022]
Example 2
Paper size by reacting in the same manner as in Example 1 except that 20 g of maleated rosin ester (maleinization rate: 8%, glycerin esterification rate: OH / COOH = 0.5) was used as the rosin ester. An agent was obtained.
[0023]
Example 3
A sizing agent for papermaking was obtained by reacting in the same manner as in Example 1 except that 19 g of benzyl chloride was used instead of epichlorohydrin as a quaternizing agent.
[0024]
Example 4
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser and dropping funnel, 100 g of isopropyl alcohol and maleated rosin ester (maleinization rate: 8%, glycerin esterification rate: OH / COOH = 0.5) 20 g Was heated to the reflux temperature and dissolved. Next, a mixed solution consisting of 70 g of styrene, 22 g of N, N-dimethylaminoethyl acrylate, and 2 g of azoisobutyronitrile is dropped into the reaction system over 2 hours from the dropping funnel, and further maintained at the same temperature for 5 hours. The reaction was completed.
Next, 70 g of isopropyl alcohol was distilled off from the obtained reaction solution, and 9 g of acetic acid and 100 g of water were further added and dissolved. Thereafter, 380 g of water and 14 g of epichlorohydrin were added, and a reaction was carried out at 80 to 85 ° C. for 3 hours to obtain a sizing agent for papermaking.
[0025]
Example 5
A sizing agent for papermaking was obtained by reacting in the same manner as in Example 4 except that 28 g of N, N-diethylaminoethyl methacrylate was used as the aminoalkyl ester.
[0026]
Example 6
A sizing agent for papermaking was obtained by reacting in the same manner as in Example 4 except that 22 g of N, N-dimethylaminopropylacrylamide was used instead of the aminoalkyl ester.
[0027]
Example 7
A sizing agent for papermaking was obtained by reacting in the same manner as in Example 4 except that the amount of styrene was 56 g and 11 g of butyl acrylate was newly added as the third component of the constituent monomer.
[0028]
<< Comparative Example 1 >>
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and dropping funnel was charged with 100 g of isopropyl alcohol, heated to reflux temperature, and then 70 g of styrene and 24 g of N, N-dimethylaminoethyl methacrylate from the dropping funnel. Then, a mixed solution composed of 2 g of azoisobutyronitrile was dropped into the reaction system over 2 hours, and the mixture was further maintained at the same temperature for 5 hours to complete the reaction. Next, 70 g of isopropyl alcohol was distilled off from the resulting reaction solution, and 9 g of acetic acid and 300 g of water were further added and dissolved to obtain a sizing agent for papermaking.
[0029]
<< Comparative Example 2 >>
To the sizing agent obtained in Comparative Example 1, 14 g of epichlorohydrin was further added and reacted at 80 to 85 ° C. for 3 hours to obtain a paper sizing agent.
[0030]
Therefore, paper was produced by alkaline papermaking using calcium carbonate as a filler using each of the papermaking sizing agents of Examples 1 to 7 and Comparative Examples 1 and 2, and the sizing test was performed.
<< Sizing Example of Paper Containing Rosin Bonded Cationic Polymer as Internal Sizing Agent >>
After adding 15% of calcium carbonate (TP-121; manufactured by Okutama Kogyo Co., Ltd.) as a filler to the beaten pulp slurry (LBKP: NBKP = 8: 2), the above Examples 1-7 And each sizing agent of Comparative Examples 1 and 2 was added in the addition amount shown in FIG. 1, and hand-made paper having a basis weight of 60 g / m ² was produced using a hand-made paper tester (TAPPI standard sheet machine) according to a conventional method.
The resulting hand-made paper is left in a constant temperature / humidity room at 20 ° C and 65% humidity for one day, and then measured for sizing degree (seconds) for each added amount of sizing agent by the Steecht method (JIS P8122). did.
[0031]
FIG. 1 shows the test results.
It was confirmed that the Steecht sizing degree of Examples 1 to 7 was larger than those of Comparative Examples 1 and 2 under the same sizing agent addition amount. Moreover, even if the addition amount of the sizing agent is reduced from 0.8% to 0.5%, in Examples 1 to 7, the reduction rate of the sizing degree is not as large as that in Comparative Examples 1 and 2, and maintains a certain level It was recognized that
Accordingly, it has been found that the sizing agent of the present invention exhibits an excellent sizing effect even during alkali sizing using calcium carbonate as a filler.
That is, a rosin-bonded cationic polymer obtained by reacting styrenes with an aminoalkyl ester or aminoacrylamide of (meth) acrylic acid in the presence of a (reinforced) rosin ester is a mixture of styrenes and (meth) acrylic acid. Since it shows an excellent size effect compared to a copolymer obtained by reacting an aminoalkyl ester or aminoacrylamide, the presence or absence of a bulky rosin ring in the polymer is the result of sizing using this polymer. It was found that the rosin-bonded polymer has a significant advantage in terms of the size effect, greatly affecting the size effect of the paper.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a chart showing the results of a sizing test on handmade paper containing each sizing agent of Examples 1 to 7 and Comparative Examples 1 and 2.

Claims (3)

(A) selected from the group consisting of rosin esters obtained by reacting rosins with polyhydric alcohols, and reinforced rosin esters obtained by reacting rosins with polyhydric alcohols and α, β-unsaturated carboxylic acids. In the presence of at least one rosin-based resin,
(B) styrenes,
(C) For papermaking comprising a water-dispersible or water-soluble rosin-bonded cationic polymer obtained by copolymerization reaction with an aminoalkyl ester of acrylic acid or methacrylic acid and cationized with a quaternizing agent or acid as an active ingredient Sizing agent. A paper sizing agent characterized in that aminoacrylamide of acrylic acid or methacrylic acid is used in place of the aminoalkyl ester of acrylic acid or methacrylic acid of (C) of claim 1. The mixing ratio of the rosin resin of (A) to both the styrene of (B) and the aminoalkyl ester or aminoacrylamide of (C) is 0.1 to 15.0% by weight. The sizing agent for papermaking according to claim 1 or 2.

Images