JPS58186696A - Size agent for papermaking - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to papermaking, and more particularly to a sizing agent for papermaking that is excellent in increasing paper strength, improving waste yield, and sizing effect in neutral papermaking.

Conventionally, rosin compounds have been used as sizing agents in paper making, and Km acid bands have been used in combination with these compounds. In recent years, anionic polyacrylamide has also been used in papermaking as a paper strength enhancer and filler retention improver.

These sizing agents are anionic and are used in acidic medium during papermaking. However, these anionic sizing agents do not have sufficient fixing properties to fine pulp, and there is a problem of white water contamination.In addition, since they are used under acidic conditions, there are problems such as equipment corrosion.

In addition, the use of inexpensive calcium carbonate as a filler has been considered, but in this case, as mentioned above, there is a risk that calcium carbonate may be decomposed in hostile media, which poses a problem in its use.

This led to the development of cation-modified sizing agents in which paper is made using a neutral or alkaline medium. Examples of such cationic denatured sizing agents include cationic denatured urine
Re1nbold: Pu1p and Paper M
AGINE OF CANADA, 68, /I6
4.110-l 12 (1967) 1-cationic starch [
Engelhardt, G., Zr218to
ffFnd papier, l 3.49,264~
270 (1964) 1 Furthermore, cationic polyamide [Nikkan Shigyo Tsui 6 No. 5551 (May 22, 1970)
)], and its use in combination with other reactive sizing agents such as alkyl ketene dimer and alkenyl succinic anhydride has been investigated. In this respect, compared to paper making using a conventional combination of anionic polyacrylamide and rosin thread size, wood is not considered to be sufficient.

In addition, attention has been paid to the cationic modification of polyvinyl alcohol (hereinafter abbreviated as PVA) from the above-mentioned cationically modified sizing agents.

Next, the cation-modified PVAK will be briefly described as follows.

A. Method for post-modifying PVA (a) In JP-A-52-368, glycidyltrimethylammonium salt [m]
A method for producing cationic PVA containing a quaternary ammonium salt by reacting with VA.

There is also 3-chloro-hydroxypropyltrimethylammonium hydrochloride which has a glycidyl group opened in the same way, but all of them have low reactivity to PVA.

(b) Journal of the Chemical Society of Japan 11. P1995~2000 (
(1975), it has been reported that cationically modified PVA is synthesized by reacting PVA[z-pichlorohydrin and then polyethylenepolyamine, but in this case, the efficiency of the etherification reaction to PVA with epichlorohydrin is low; Furthermore, the two-step reaction may complicate production.

(c) Special Publication No. 30-5563, Special Publication No. 31-3319
Also in the issue of Polymer Papers IJ, 843 (
(1977) reported the introduction of amino groups by aminoacetalization of PVA, but there is a problem because aminoacetal is expensive.

B. A method of copolymerizing vinyl acetate and a cationic monomer and then saponifying the co-electrolyte to obtain cationized PVA. An example has been shown in which cationized PVA is obtained by copolymerization, but the copolymerization rate is said to be extremely slow.

(b) In JP-A No. 56-14504, aminoalkyl acrylamide, such as CHI = CHC0N)lcH*c)ls CHN(CHs)z, and vinyl acetate were co-merged by saponification as a cationic monomer. A method for producing cationized PVA' is presented. In this case, cationized PVA can be produced, but there is a problem in terms of the copolymerizability of aminoalkyl acrylamide and vinyl acetate, which is extremely poor.

(c) According to JP-A No. 56-88413, and according to the gist of the claims, H1 1 H3 ++CHt ch-+ C0R R+, Ra, Rs are lower alkyl groups R4 is a hydrogen atom, or lower alkyl group n = integer from 2 to 6
X: Inorganic negative group It is a cationized PVA having the above-mentioned structure, and it is disclosed that it is a paper strength enhancer having this as a main component.

) In JP-A-56-118997, according to the gist of the claims, R.

] n=1-10 In the above formula, RI is an alkyl group or a hydroxyalkyl group Rm and R3 are hydrogen or an alkyl group R3 and R4 are an alkyl group X... Inorganic anion A - Amide nitrogen or rl * Groups (a), (b) of cationic groups represented by the above structure,
P including 181 or 2 buildings selected from (e), ld)
A paper manufacturing method is disclosed in which a VA-based resin is added to a pulp dispersion.

The above proposals for cation-modified PVA are presented. In A,), PVA is PVA [PVA that has added cationic properties by reacting with a cationizing agent, and in B5), vinyl acetate and a cationic columnar material are used. -, and this co-unit is saponified to obtain cationized PVA.

In Method A, it is known that it is quite difficult to cause PVA to react with a cationizing agent. In addition, in method B, cationic PVA is obtained by first copolymerizing cationic columnar polymers and vinyl acetate, and then saponifying this to obtain cationized PVA. This is due to the two-film force formula! 18! I411 release properties are also estimated in the production method, and even if the size effect of cationized PVA is improved, it is thought that there will be problems in industrialization.

Furthermore, in the detailed description of the invention column of the specification of JP-A-56-88413, from line 17 of the lower right corner of JP-A-56-88413 to line 5 of the negative side of JP-A-84, there are
Although the synthetic method of introducing cationic groups by post-modification of VA is possible in the laboratory, it has the following difficulties in industrial use.

For example, 1. It is difficult to produce a material with a certain degree of modification (cationicity).

■ Polymers often involve crosslinking reactions (grafting) and tend to become insolubilized.

Ken: Manufacturing costs are generally high.

It points out the difficulties in manufacturing and business.

Furthermore, it should be noted that in the detailed description of the invention in the specification of the same issue, from the 11th line of the left column of the 84th negative to the 5th line of the right column of the same, aminoalkyl as a cation columnar It is known that methacrylates are industrially reproduced and that they are copolymerized with respective free monomers to obtain cationic copolymers. In this case, it is co-monomed with vinyl acetate as a co-electrolytic monomer, but when this copolymer is saponified, it is saponified at the same time as the ester bond of aminoalkyl methacrylate, and the resulting modified PVA contains cationic groups. It was pointed out that it would be impossible to hold back (・
Ru.

However, despite the above-mentioned reasons, we have been researching the grafting of PVA and found that by grafting aminoalkyl methacrylate, which is a cationic monomer, to PVA, it is possible to obtain vinyl as papermaking size All. We were able to invent a cationized PVA that exhibits a size effect similar to or greater than that of the cationized PVA obtained by saponifying a copolymer of a 7-mer and a cationic monomer.

That is, an object of the present invention is to provide, at low cost, a cationized PVA that improves sizing, paper quality, or filler fixing properties as a sizing agent for papermaking. Cationized PV obtained by graft copolymerization of aminoalkyl methacrylate on PVAK cationic seven pillars or aminoalkyl acrylate
A is the main sizing agent for papermaking.

The cationized PVA according to the present invention as described in 5 above is a commonly used PVA, and the cationic monomer to be grafted onto it may be a 41R1...ethyl group or a 2-oxyhydroglobyl group R1. ...Methyl group or ethyl group desirable.

In addition, unlike the above-mentioned reference, the cationized PVA according to the present invention is produced by copolymerizing a vinyl heptamer and a cationic monomer and then saponifying the comonomer.
Cationized PV grafted onto K-cationic seven pillars
Since it is A and there is no saponification process after 18 grafts,
The ester bonds of the cationic monomers do not undergo decomposition during saponification (the main feature of the present invention is that a predetermined amount of cationic groups can be introduced).Next, the aminoalkyl methacrylate is grafted onto the PVA. As for the method of copolymerization.

(a) A homogeneous graft copolymerization method in which an aminoalkyl methacrylate is dissolved in a PVA water bath solution at a predetermined concentration and combined using a water bath type 1 initiator.

(b) A heterogeneous graft copolymerization method in which PVA is suspended in a mixed solvent of water and a non-solvent of PVA, and a water-bathable 1-polymer initiator and an aminoalkyl methacrylate are added thereto and mixed.

The graft copolymerization method shown in the figure is preferable due to its high grafting efficiency, but in this case, if you want to obtain cationized PVA in powder form, you have to go through 5 complicated steps, such as precipitation → p-filtration → drying → pulverization. Must be.

However, in (a), the grafted cationized P
In addition to VA, a homopolymer of aminoalkyl methacrylate is also mixed. This is.

Naturally, since it is a cationic polymer, even if the graft co-electrolyte mixture is used as it is for sizing in the papermaking process, it will not impede the performance of the target cationized PVA, and in some cases, it is expected that it will warp and have a complementary effect. Ru.

Furthermore, in the graft copolymerization method (b), although the grafting is less uniform than in the method (a), it is easier to take out as a modified PVA powder. That is, there is an advantage that post-processing as a product is easy.

Next, there are no special restrictions on the PVA used in the present invention, but the average degree of polymerization is 200 to 3000, and the saponification is 60.
mole % or more is used. Also, acrylamide, ethylenically unsaturated phase carboxylate, olefin, α-olefin.

BWUjflk PVAK, which is a combination of vinyl, vinyl ether, etc., is used.

In addition, as for the aminoalkyl methacrylate which is a cationic columnar member, as described above, the amount of aminoalkyl methacrylate to be co-electronized with the PVAK graft is determined based on the monomer monomer relative to the constituent unit of the PVA. The unit is 0.01 to 10 mol %, but when it exceeds 10 mol %, PVA gels and becomes sticky when soaked in water. 0.5~5
．． 0 mol% is preferred. It should be noted that these grafted cationized PVAs according to the present invention are also largely water soluble.

Next, as a 1-polymer initiator used for graft copolymerization,
persulfates, such as potassium persulfate, ammonium persulfate, or sodium persulfate, hydrogen peroxide, cerium salts, such as cerium ammonium nitrate;
A redox system using a combination of an initiator and a reducing agent is also used. Examples of reducing agents include sodium hyposulfite, acidic sodium sulfite, Rongalite, iron salts, and lithium halides.

Next, the cationized PVA of the present invention is added to the aqueous dispersion of paper bulbs and fixed on the pulp fibers, or a filler is added at the same time, and the cationized PVA of the present invention is added to the aqueous dispersion of paper bulbs and then used for paper making. Dry and use as a product.

It can also be used by spraying or impregnating with a size press. As mentioned above, the amount of internal addition in paper making varies depending on the type of paper pulp fiber and its purpose, but it is 0.05 to 5.01 kK per 11 kK of dry pulp.
It is preferably 0.1 to 2.031% by weight.

In this case, if it is less than 0.051% by weight, the paper strength increasing effect will be 5%.

5] If iL is 1% or more, the paper strength increasing effect is hardly improved.

In addition, cationized PVA related to unexploded uA is effective in making neutral paper using calcium carbonate as an additive, but Merck, titanium oxide, clay, etc. can also be used as an additive, and it can be used in combination with other paper sizing agents. It may also be used in combination with cationic polyacrylamide or cationic starch.

As described above, the effect of the cationized PVA according to the present invention as a paper sizing agent is that it is water-soluble, and unlike conventional cationized PVA, it is easy to manufacture and is inexpensive. In addition, in neutral papermaking, when internally added, calcium carbonate (4C, Il agent) has good fixation to the pulp fibers, and the yield improves. Therefore, P water resistance in paper making is good, and white water treatment becomes easier. The paper thus obtained was able to improve the strength of the paper, such as bursting strength, and improve the size effect, such as improved sizing.

Next, examples of cationized PVA according to the present invention will be shown.

Example 1. .

After mixing 109 parts of PVA (average degree of submergence 2.400, degree of saponification 99.0 mol%) with 900 parts of water.

After adding 20 parts of dimethylamine ethyl methacrylate and removing dissolved oxygen by ventilating the reactor for 1 hour, 0.6 part of potassium persulfate was added and the temperature was raised to 45°C to start graft copolymerization. After 3 hours, the temperature was further raised to 85°C, and after 1 hour, polymerization was completed, and then neutralized with hydrochloric acid. The resulting polymer bath solution was dropped into 3 times the volume of methanol to precipitate only the graft polymer, which was then filtered and dried.

The resulting graft polymer was water-removed using a Soxhlet extractor with methanol, and the nitrogen content was measured by the Kieldahl method to be 0.35% by weight, and the cation modification rate was 1.13 mol%. Ta.

Next, as a raw material for paper pulp, Canadian Freeness 35
Add 1% water bath solution of cationized PVA of this example to 0ml of 3% aqueous dispersion of L-BKP at a rate of 2o, 4% based on the amount of pulp.
Add 0.60 t% of each, further dilute the KL-BKP dispersion concentration to 0.3%, keep the pH at 7-8, and add J I 5.
Based on the paper making method of K8209, tsubo t60±5 t/? Paper is made so that it becomes 3.5 V4 / m''
After press dehydration for a minute, the resulting paper was dried at 110° C. for 5 minutes and conditioned at 20° C. and 65% RH for 48 hours.

On the other hand, the white water during paper making was collected and concentrated, the concentration of cationized PVA in the white water was determined by the iodine coloring method, and from this the fixation rate of cationized PVA to the pulp was determined, and the fixation rate was 74° and 78. It was 82%. Furthermore, the tearing length of the paper after humidity conditioning was measured using a tensile tester/tensile tester based on JISK81134C, and JISK8
The specific rupture degree was measured using a Mullen rupture tester based on No. 112. These results are shown in Table 1 below.

Example 2 150 parts of PVA (average content: 1750. Silication [99.5 mol%)] 14 parts of trauryl alcohol-sulfate ester soda (Daichi Kogyo Seiyaku Co., Ltd., Monogen Y-100) were dissolved in 850 parts of water. Then, 30 parts of dimethylamine ethyl methacrylate, 0.3 parts of potassium persulfate, and 0.06 parts of acidic sodium sulfite were added to obtain canonized PVAk in the same manner as in the example. In addition, the obtained cationized PVA
The nitrogen content therein was 0.61%, and the cation modification rate determined as the result was 2.01 mol%. In this case, the cation modification rate of cationized PVA can also be determined by nuclear magnetic resonance spectroscopy. That is, according to the proton nuclear magnetic resonance spectrum of the heavy aqueous solution of cationized PVA in this example, the absorption at the Schiff) 2.6 ppm position is HmC=C of the dimethyl-minoethyl methacrylate unit.
(CHs) COOCHaCHzN (CHs) From the CHmK assignment of the ethyl moiety in the example and the comparison value between this absorption intensity and the absorption intensity of H shift 1.6 ppm, the amount of grafting of the cationic monomer determined above is determined.

That is, the cation modification rate is 1.98 mol%, which is almost the same as 2.01 mol% determined from the nitrogen content of 1.0 by the Kierdal method, so the cation modification rate is 1.98 mol%. Can be used.

Furthermore, Example 1. A paper was made in the same manner as in the example using the cationized PVA of this example in place of the cationized PVAK of 1, and the properties of the paper are also listed in Table 1.

Example 3゜PVA (average polymerization [1750, degree of saponification 99.5 mol%
) 150 parts, water 850 parts, 3-trimethylaminochloride-2-hydroxypropyl methacrylate 15 parts, and the others were as in Example 1. Graft copolymerization was carried out under the same conditions.゛The composition of the obtained combined bath solution was 15.25% of cationized PVA as well as isolated cationized PV consisting of a homopolymer of 3-trimethylaminochloride-2-hydroxyglobin methacrylate.
The nitrogen content of A was 0.18%, and the cation modification rate was 0.59 mol%. Note that the solution of this example was used as it was in Example 1. A paper was made in the same manner as above, and the characteristics of this play were also listed in Table 281.

Example 4 150 parts of PVA (average 1 (degree of content 1750, degree of saponification 99.5 mol%) was added to 850 parts of water at 30°C, and PVA
While still undissolved, 0.3 parts of potassium persulfate and 0.06 parts of acidic sulfite were added and stirring was continued. After 5 hours, 30 parts of dimethylamino-ethyl methacrylate was added and the graft mixture was heated at 30°C for 5 hours. After the combination, the mixture was immediately passed through K (p) and dried.

The cation ratio PVA obtained in this case is different from the cation modification of cationized PVA in Example 1, and is presumed to be non-uniform because some in-phase reactions also occur.
The advantage is that the isolation of VA is extremely simple.

The nitrogen content of the obtained cationized PVA was 0.30%,
Therefore, the modification rate was 1.0 mol%.

Example 1 using the cationized PVA of this example. Similar tests were conducted on paper obtained by paper making under the same conditions as above, and the results and characteristics are also listed in Table 1.

Comparative Example 1゜In place of the cationized PVA of Example 1, PVA [average 1
degree 2400. Saponification degree 99. Table 1 shows the characteristic values obtained by the same test method for paper obtained by making paper in the same manner as in Example 1 using They are also listed for comparison.

Example 5゜Example 2. Using cationized PVA, calcium carbonate (NITOREX-7 manufactured by Nitto Funka Kogyo Co., Ltd.
0) was added at 30% to the pulp violet, and while stirring, the cationized PVA was added to the pulp violet at a rate of 0.2.0.4.
0.6% each was added, and paper was made to have a basis weight of 60±5f/- based on the papermaking method of JIS K8209.
After press dehydration at 1/- for 5 minutes, it was dried at 110°C for 5 minutes. About the paper thus obtained.

It was wetted for 48 hours at 20° C. and 65% RH.

The calcium carbonate content of this paper was determined, the ratio of added calcium carbonate to tit was determined, and the yield rate was determined. In addition, based on JISK8113, the temporary cutting was measured using a Tensilon tensile tester, and JISK8112
Based on this, the specific rupture degree was determined using a Mielen rupture tester. The respective results are shown in Table 2.

Comparative Example 2 Example 5. In place of the cationized PVA of Example 2, PVA r average degree of 1 was 1750. Saponification [99,5
Paper was obtained using the paper making method under the same conditions as in Example 5 using mol % (-17) of Denki Kagaku Kuri Co., Ltd.*. The characteristic values of this paper are also listed in Table 2 for comparison.

Example 6゜Example 2 JCi [used instead of PVAc? , using PVA (average degree of polymerization 550, degree of saponification 88.4 mol%), Example 2. A grafted polymer was obtained in the same manner as described above. Regarding the cationized PVA obtained in this way, the Nitjingu Fukuta was 1.11%, and when used, the cationic modification rate was 3.8%.
It was 0 mol%.

Next, add calcium carbonate (Nitto Powder Kako 4N) to several liquids of 0.3% water of Canadian Freeness 320ml
r'l"0REX-70) was added to the pulp at 30%, and then alkyl ketene dimer (Arayo Kagaku, Nizbein-900) was added as a sizing agent at 0.0% to the pulp.
In addition, 0.2.0% and 4.0.6% of the cationized PVA of this example were added to the pulp, and the following Example 5. The paper was prepared using the same papermaking method.

The yield rate of calcium carbonate in this paper is terrible.

The specific crack strength was measured, and the Surakicht size degree was also measured based on the TAPPI standard test method, and these measured values are also listed in Table 3.

Comparative Example 3 In Example 6-, the same cationized PVAK was replaced with P
A paper was made using VA (average degree of polymerization 550, degree of saponification 88.4 mol%) using the same paper making method as in the example.

The above-mentioned measured physical property values for this paper were also listed in the 8g3 table for comparison.

From Table 1, the cationized PVA according to the present invention is untreated P
Compared to VA, this shows that the strength of the paper quality is improved when used as a sizing agent in paper making. Furthermore, from this table, it can be seen that the cationized PVA whose nonuniformity was graphed in Examples 4 and 5 had almost the same paper strength as the cationized PVA whose uniformity was graphed in Examples 1 and 2.3. What is shown is interesting and has significance in terms of industrialization.

Next, in Table 2, the fixation state of the filler calcium carbonate to the pulp in paper making was compared using the cationized PVA of Example 2 and the untreated PVA. It shows that there are many things.

In Table 3, different bases, for example, 550,
Using something like 88.4 mol% of saponified If, cationized PVA was prepared by graft copolymerization, and the obtained cationized PVAt was used to make paper in the same manner as above. It shows that there is almost no difference from the cationized PVA of the example. In this case, it has been shown that the degree of Surakicht size is also particularly improved.

As described above, the cationized PVA according to the present invention has sufficient effects as a sizing agent for paper making, such as increasing the sizing degree and strength of paper quality, and also has good fixation to paper pulp, and is particularly useful as an additive.

The retention rate of calcium carbonate is also high. In addition, the water resistance during paper making is excellent, and therefore white water treatment is also good. It should be noted that this method is easier to manufacture and can be supplied at a lower cost than cationized PVA produced by conventional methods.

Furthermore, the cationized PVA according to the present invention is expected to be applied not only as a sizing agent for paper making, but also as a surface sizing agent for paper, an antistatic agent, a flocculant for polymers, an emulsifier for emulsions, a paste for household use, etc. .

Patent Applicant Denki Kagaku Kogyo Co., Ltd. Agent Patent Attorney Department Toshido Patent Attorney Mikio Segawa Procedural Amendment September 10, 1981 1, Case Indication 1982 Uro! lfi'fi” Application No. 67203 Special
3. Relationship with the case of the person making the amendment Patent applicant address 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Representative
Akira Shinohara 4, agent address: 1-112-1''F3 Ebisu Nishi, Shibuya-ku, Tokyo
09 Name (8073) Patent Attorney 7iM River
5. Date of amendment order Vol. 6. Number of inventions to be increased by amendment 7. Details subject to amendment: Hiiragi Full text correction 8. Contents of amendment ゛ As shown in the attached sheet (rev. E) - Particulars number ■, Invention Name: Internal additive for papermaking 2, Claims (1) An internal additive for papermaking mainly consisting of cationized polyvinyl alcohol obtained by graft copolymerizing aminoalkyl ivy acrylate or aminoalkyl acrylate to polyvinyl alcohol.

(2) Aminoalkyl methacrylate or aminoalkyl acrylate is a cationic monomer (-2 R... -H or methyl group R1... -ethyl group or 2-hydroquinopropyl group R2
*@ ◆ Methyl group or ethyl group
The internal additive for paper making described in Section 1 of I14, i1;

(3) The internal additive for papermaking according to claim 1, wherein the cationized polyvinyl alcohol is the polyvinyl alcohol at the 1111 position, and 10 moles or less of a cationic monomer is grafted thereto.

3. Detailed Description of the Invention The present invention relates to paper making, especially 11 (neutral paper making 6C).
+9.1 for internal correction 1. Conventionally, a rosin compound has been used as a sizing agent in paper making, and a sulfuric acid band has been used in combination with this. Ma" ,
In tl'i iL'r, paper making
In order to improve filler yield, anionic polyacrylamide is used in combination with polyacrylamide. Internal additives do not have sufficient adhesion to pulp fibers, and there is a problem of white water contamination.
In addition, since it is used under acidic conditions, there are problems such as equipment corrosion.

In addition, the use of inexpensive calcium carbonate as a filler has been considered, but in this case, as mentioned above, there is a risk that calcium carbonate may be decomposed in an acidic medium, which poses a problem in its use.

This led to the development of internal correction in which paper is made using a neutral or alkaline medium.

In addition, examples of such cationically modified internal additives include cationically modified urea resins (Kenta Toyoshima Nishiba Technical Association Journal,
Vol. 22, No. 2 (1967)), melamine resin (Re 1
nbold: Pu1p and Paper Mag
agine of Canada 68, N014.1
10-112 (1967)) Cationic starch (Eng.
elhardt, G., Zellstoff
andPapier, 13, No. 9.264-27
0 (1967)) Furthermore, cationic polyamide (Nikkan Shigyo Tsushin No. 5551 (May 22, 1970))
), and its use in combination with other reactive sizing agents such as alkyl stingers/dimers and alkenyl succinic anhydrides is being considered.

These cationic propensity corrections themselves have four positive charges,
Therefore, for example, cationic internal additives that are generally added during beating can easily combine with the fiber pulp, which has a negative charge, and can easily combine with the valve, resulting in less turbidity of white water (filtrate) as described above, and the pH of the liquid. Since the neutral gusset is alkaline, it has the advantage of being less likely to corrode paper-making equipment, but conventional products are not said to be sufficient in terms of increasing paper quality, improving size change, or especially product cost. For this reason, cationic modification of polyvinyl alcohol (hereinafter abbreviated as PVA) has been attracting attention as a cationic property correction as described above.

Next, conventional cation-modified PVA will be briefly described as follows.

A. Method for post-modifying PVA (a) In JP-A-52-368, glycidyltrimethylammonium salt n.! Method 1 of producing cationic PVA containing 4g57 ammonium salt by reacting the salt with PVA in the presence of an alkali catalyst, and 3-10 row 2 in which the glycidyl group was similarly opened.
-Hydroxypropyltrimethylammonium hydrochloride has also been reported to be used in the reaction←) Journal of the Chemical Society of Japan 1975 (11) P1995-20
In 00, PVA was reacted with epichlorohydrin,
Furthermore, it has been reported that cationically modified PVA is synthesized by reacting polyethylene polyamine.

(c) Special Publication No. 30-5563, Special Publication No. 31-3319
In the same issue, polymer paper Lee 14,843 (19
77), the introduction of amine groups by aminoacetalization of pvA was reported.

B1 A method of copolymerizing vinyl acetate and a cationic monomer and then saponifying the copolymer to obtain cationized PVA. Example of obtaining cationized PVA by saponifying co-monomerization (b) JP-A-56-145
04, aminoalkyl acrylamide as cationic monomer, for example CH2=CHCONHCi(2CH2CH2N (C
A method has been proposed for producing cationized PVA by saponifying a copolymer of Hs') 2CH3 (Cf(3) a C1○ and vinyl acetate).

(c) According to the gist of the claims in JP-A-56-88413, CH3 (CH2C) + (CH2CH)-1 CONH-(CH2) n -A OHCH3 + (CH2CH) COR4 RI%, R2 and R3 are lower alkyl groups R4 is a hydrogen atom or a lower alkyl group R2R3 n = an integer of 2 to 6 It is disclosed that it is a paper strength enhancer.

) In JP-A No. 56-118997, according to the gist of the claims, \ 4 5 1 \ R i 5 \ 4 n = 1 to 10 In the above formula, RI represents alkylene or hydroxyalkylene groups R2 and R5 is hydrogen or an alkyl group R3 and R4 are an alkyl group
PV containing one or two types selected from (C) and (d)
A paper manufacturing method is disclosed in which A-based resin is added to a pulp dispersion.

The above is a proposal for cationically modified PVA using conventional methods.
In 1), vinyl acetate is copolymerized with a cationic monomer, and this copolymer is made into a care to obtain cationized PVA.

In Method A, it is known that it is quite difficult to cause PVA to react with a cationizing agent. In addition, in method B, after first copolymerizing a cationic monomer and vinyl acetate, this is saponified to obtain cationized PVA, but the copolymerization is generally poor, and furthermore, a second membrane force method is used to saponify this. Therefore, it is assumed that there are difficulties in the manufacturing method, and even if the effect of internal addition as cationized PVA is improved, it is thought that there will be problems in industrialization.

Furthermore, in the detailed description of the invention in the specification of JP-A-56-88413, from the 83rd day of the same, from the lower right column, line 17 to the same page, 84th page, line 5, there are
Although the synthetic method of introducing a cationic group by post-modification of VA is possible in the laboratory, there are the following difficulties in industrial use.

For example, (1) It is difficult to produce products with a certain degree of modification (cationicity).

■ Polymers often involve crosslinking reactions (grafting) and tend to become insolubilized.

■ Manufacturing costs are generally high 4. It points out the difficulties in manufacturing and business.

Furthermore, it should be noted that in the description of the specification of the same issue, from page 84, column 5, line 11 to column 5, line 5 of the right column of the same issue, aminoalkyl methacrylate is used as a cationic monomer. It is known that cationic copolymers are produced industrially and copolymerized with various monomers to obtain cationic copolymers. In this case, the copolymerized mono 7- is copolymerized with vinyl acetate, but when this copolymer is saponified, the ester bonds of the aminoalkyl methacrylate are simultaneously saponified, and the resulting modified PVA contains cationic groups. It has been pointed out that it becomes impossible to restrain people.

However, despite the above reasons, we have been studying the grafting of PvA, and by grafting the cationic monomer aminoalkyl methacrylate or a,minoalkyl acrylate to PVA,
The purpose is to provide a cationized PVA that exhibits an internal addition effect similar to or better than that of the cationized PVA obtained by saponifying a copolymer of a vinyl monomer and a cationic monomer as described above for papermaking correction. It is.

That is, based on the present invention, the purpose is to provide cationized PVA that improves filler fixability, paper strength, sizing, etc. as a paper-making internal correction at a low cost with an easy manufacturing method. In the present invention, cationic PVA obtained by graft copolymerizing PVA with a cationic monomer such as amine alkyl methacrylate or aminoalkyl acrylate is the main component for paper-making internal correction.

As mentioned above, the cationized PvA according to the present invention is a commonly used PVA, and the cationic monomer to be grafted onto it, for example, R...H, methyl group R1...ethyl group, 2- Hydroxypropyl group R2...Methyl group or ethyl group

The shredded cationized PVA according to the present invention differs from that obtained by copolymerizing a vinyl monomer and a cationic monomer and then saponifying this copolymer, as in the above-mentioned reference, in that it has Pv
Cationized P obtained by grafting a cationic monomer onto A
Since it is VA and there is no saponification step after graft copolymerization,
A feature of the present invention is that a predetermined amount of cationic groups can be introduced without the ester bond of the cationic monomer being decomposed during saponification.

Next, the production of cationic PVA based on the present invention will be explained.

Methods for graft copolymerizing aminoalkyl methacrylate with PVA include (a) a homogeneous graft copolymerization method in which a predetermined amount of aminoalkyl methacrylate is dissolved in an aqueous PvA solution and polymerized using a water-soluble polymerization initiator;

(b) A heterogeneous graft copolymerization method in which PVA is suspended in a mixed solvent of water and a non-solvent of PVA, and a water-bathable polymerization initiator and aminoalkyl methacrylate are added and polymerized.

The graft copolymerization method (a) is preferable due to its high graft efficiency, but in this case, if you want to obtain cationized PVA in powder form, you have to go through complicated steps such as precipitation, filtration, drying, and pulverization. However, in (a), the grafted cationized P
In addition to VA, homopolymers of aminoalkyl methacrylate are also present. Since this product is naturally a cationic polymer, even if the graft copolymerization solution is used as it is in the papermaking process, it will not inhibit the performance of the target cationized PVA, and in some cases, a synergistic effect is also expected. .

Furthermore, in the graft copolymerization method (b), although the grafting is less uniform than in the method (a), it is easier to take out as a modified PVA powder. In other words, its place as a product.''4. (
It has the advantage of being easy to buy.

Next, there are no particular restrictions on the PVA used in the present invention, but the average degree of polymerization is 200 to 3000, and the saponification is 60.
More than mulch is used. i! acrylamide, ethylenically unsaturated carboxylate, olefin, α-
Used in PVA copolymerized with olefin fatty acid vinyl, vinyl ether, etc.

The cationic monomer aminoalkyl methacrylate or aminoalkyl acrylate is as described above, but the wrinkles of the aminoalkyl methacrylate or aminoalkyl acrylate graft copolymerized to PVA are ☆° is 0.01 to 10 molt per monomer medium, but l
When the amount exceeds O molti, PVA gels and becomes difficult to dissolve in water. Therefore, the internal additive is preferably 0.5 to 5.0 mol. Furthermore, PVA grafted with aminoalkyl acrylate can also be obtained in exactly the same manner. A major feature of these grafted cationized PVAs according to the present invention is that they are water-soluble.

Polymerization initiators used in the graft copolymerization mentioned above include persulfates, such as potassium persulfate, ammonium persulfate, or sodium persulfate, hydrogen peroxide, cerium salts, such as cerium ammonium nitrate, etc. A redox system that uses a combination of an agent and a reducing agent is also used. As reducing agents, sodium chloride, acidic sodium sulfite,
There are Rongarit, iron salts, lithium rogenide, etc.

Next, the cationized PVA of the present invention is added to the aqueous dispersion during beating of the paper valve, like a general internal additive for papermaking,
A filler is added to the pulp fibers or at the same time, and the paper is made and dried to produce a product.

In addition, method 2 of spraying or impregnation coating using a size press or the like can also be used. As mentioned above, the amount added internally in paper making varies depending on the type of paper pulp fiber and its use, but it is 0.05 to 5.0% based on the amount of dry pulp.
It is preferably 0% by weight, preferably 0.1 to 2.0% by weight. In this case, if it is less than 0.05% by weight, the paper strength enhancing effect will be weak, and if it exceeds 5% by weight, the paper strength enhancing effect will hardly be improved.

In addition, the cationized PVA according to the present invention is effective in making neutral paper using carbonate as a filler, but talc, titanium oxide, clay, etc. can also be used as a filler, and it can be used in combination with other paper-making sizing agents. It may also be used in combination with cationic polyacrylamide or cationic starch.

As described above, the effects of the cationized PvA according to the present invention as an internal additive for papermaking are that it is water-soluble, and unlike conventional cationized PVA, it is easy to manufacture and is cost effective. It is inexpensive, and even when added internally in neutral papermaking, it has good fixing properties to pulp fibers, and at the same time, it also fixes calcium carbonate as a filler well and improves yield. Therefore, the drainage property in paper making is good, and white water treatment becomes easier. The paper produced in this way has improved effects such as improved paper strength, such as improved bursting strength, and improved sizing.

Next, examples of cationized PVA according to the present invention will be shown.

Example 1 After dissolving 100 parts of PVA (average degree of polymerization 2.400, degree of saponification 99.0 mol%) in 900 parts of water, 20 parts of dimethylamine ethyl methacrylate was added and the domine was replaced for 1 hour. After removing dissolved oxygen, potassium persulfate 0
．． 6 parts was added, the temperature was raised to 45°C to start graft copolymerization, the temperature was further raised to 85°C after 3 hours, the polymerization was completed after 1 hour, and the resulting polymer solution was neutralized with hydrochloric acid. was added dropwise to methanol with a 3-fold lid to precipitate only the graft polymer, which was then filtered and dried.

The resulting graft polymer was water-removed using a Soxhlet extractor with methanol, and the nitrogen content was measured by the Kieldahl method, and the result was 0.35% by weight, and the cation modification rate was 1.13 mol. .

Next, as a raw material for paper pulp, Canadian Freeness 35
The cationized PVA of this example was added to a 3% aqueous dispersion of 0 mJ of L-BKP at a temperature of 0°2.0.4.0.
6 each was added, and the concentration of L-BKP dispersion was further increased to 0.3%.
The paper was diluted to pH 7 to 8, and paper was made to have a basis weight of 60±s g/, l based on the paper making method of JIS K8209, and after dehydration by pressing at 3.5 Kg/m for 5 minutes, Dry the paper at 110°C for 5 minutes and dry it at 20°C.
The humidity was controlled at 165% RH for 48 hours.

On the other hand, the white water during paper making was collected and concentrated, the concentration of cationized PVA in the white water was determined by the iodine coloring method, and from this the fixation rate of cationized PVA to the pulp was determined, and the fixation rate was 74.78. It was 82%. Furthermore, the tearing length of the paper after humidity conditioning was measured using a Tensilon tensile tester based on JISK8113, and JISK81
The specific rupture degree was measured using a Mullen rupture tester based on No. 12. These results are shown in Table 1 below.

Example 2 150 parts of PVA (average degree of polymerization 1750, degree of saponification 99.5 mol%) and 14 parts of lauryl alcohol acid ester soda (Daiichi Kogyo Seiyaku Co., Ltd., Monogen Y-100) were mixed with 8 parts of water.
50 parts of dimethylaminoethyl methacrylate 30 f. , :r, 0.3 part of potassium persulfate, and 0.06 part of acidic sulfite seeder were added to prepare Example 1. Cationized PVA was obtained in a similar manner. In addition, the nitrogen content in the obtained cationized PVA was 0.61%, and the cation modification rate determined as a result was 2.01 mol.
In this case, the cation modification rate of cationized PVA can also be determined by nuclear magnetic resonance spectroscopy. That is, according to the proton nuclear magnetic resonance spectrum of the heavy water solution of cationized PVA in this example, the absorption at the shift 2, 6 ppm position is H2C = C (CH3) COOCH2 CH2 of the dimethylaminoethyl methacrylate unit.
C)(2) of the ethyl moiety of N(CH3)2, and this absorption intensity and PVA unit -CH2CH(
r) From the comparison value with the absorption intensity of 1.6 ppm of CH 2 K licks / H ft, the amount of grafting of the cationic monomer determined above, that is, the cation modification rate is 1.98 mol, which is determined by the Kieldahl method. Since it almost matches the 2.01 molti determined from the nitrogen content, the cation modification rate can be used with any drawing method.

Furthermore, a paper was made in the same manner as in the example using the cationized PVA of this example instead of the cationized PVA of Example 1.0, and the properties of the paper are also listed in Table 1.

Example 3.

P'VA (average degree of polymerization 1750, degree of 'I-7' 99.

5 mol %), 850 parts of water, 15 parts of 3-trimethylammonium chloride-2-hydroxypropyl methacrylate, and the rest was as in Example 1. Graft copolymerization was carried out under the same conditions.

The composition of the obtained polymer solution was cationized PVA15.2
5% plus 3-trimethylammonium chloride-2
- Isolated film consisting of a homopolymer of hydroquine glovir methacrylate 2f? : The nitrogen content of the cationized PvA was 0.18%, and therefore the cation modification rate was 0.59 molar. The polymerization solution of this example was used as it was in Example 1. Create paper by making paper in the same way as
The characteristics of this paper are also listed in Table 1 [2t(.

Example 4.

PVA (average polymerization twt 7s o, degree of saponification 9
9.

5 mol%) was added to 850 parts of water at 30°C, and P
While vA remains undissolved, add 0.3 parts of potassium persulfate, gO. After 5 hours, 30 parts of dimethylamine ethyl methacrylate was added and the mixture was heated at 30°C.
After graft copolymerization was carried out for 5 hours, the mixture was neutralized with hydrochloric acid, immediately filtered, and dried.

The cationized PVA obtained in this case is different from the cationic modification of cationized PVAO in Example 1, and is presumed to be heterogeneous because a portion of the solid phase reaction is also performed, but the isolation of the cationized PVA is It has the advantage of being very simple.

The nitrogen content of the obtained cationized PVA was 0.

30 mol. Therefore, the modification rate was 1.0 mol.

Example 1 using the cationized PVA of this example. Similar tests were conducted on paper obtained by paper making under the same conditions as above, and the results and characteristics are also listed in Table 1.

Comparative example 1.

Example 1. Paper was made in the same manner as in Example 1 using PvA (average degree of polymerization 2400, degree of saponification 99.0 molt (manufactured by Denki Kagaku Kogyo Co., Ltd. -24)) instead of cationized PVA. The characteristic values obtained for the obtained paper using the same test method are also listed in Table 1 for comparison.

Example 5.

Example 2. Cal/rum carbonate (NITOREX-70 manufactured by Nitto Funka Kogyo Co., Ltd.
) was added at 30% based on the amount of pulp, and while stirring, the cationized PVA was added at 0.2, 0.4, 0% based on the amount of pulp.
．． 6 each was added, paper was made according to the paper making method of JIS K8209 so that the weight was 60 + L5 g/m, and after dehydration by pressing at 3.5 Kg/crn' for 5 minutes, 110
It was dried at ℃ for 5 minutes. Regarding the paper obtained in this way,
The humidity was controlled at 20° C. and 165% RH for 48 hours.

The amount of calcium carbonate contained in this paper was determined, the ratio to the total amount of added calcium carbonate was determined, and the yield rate was determined. Furthermore, the tearing length was measured using a Tensilon tensile tester based on JISK8113, and the specific degree of manufacture was measured using a Mieren bursting tester based on JISK8112. The respective results are shown in Table 2.

Comparative Example 2゜Example 5. In Example 2. PVA (average degree of polymerization 1750, degree of saponification 99.5
Example 5. Paper was obtained using the paper making method under the same conditions. The characteristic values of this paper are also listed in Table 2 for comparison.

Example 6゜Example 2. In place of the PVA used in Example 2, PVA (average degree of polymerization 550, degree of saponification 88.4 mol%) was used. A grafted polymer was obtained in the same manner as described above. The nitrogen content of the cationized PVA thus obtained was 1.11%, and therefore the cationic modification rate was 3.80%.
It was morchi.

Next, Canadian Freeness 320ml L-BKP
Calcium carbonate (Nitto Funka Kogyo N.
Add 30 g of ITOREX-70) to the pulp,
Next, as a sizing agent, 0.4% of alkyl ketene dimer (Buyo Kagaku, Seishhain ni-900) was added to the pulp.
Furthermore, 0.2, 0.4, 0.6 each of the cationized PVA of this example was added to the pulp, and the following Example 5. The paper was prepared using the same papermaking method.

The calcium carbonate yield, tear length, and specific tear strength of these papers were measured, and the Steckigt sizing degree was also measured based on the TAPPI standard test method, and these measured values are also listed in Table 3. Comparative example 3゜Example 6. In place of the same cationized PVA, P
VA (average degree of polymerization 550, degree of saponification 88.4 mol)
A paper was prepared using the same paper making method as in the example.

The above measured physical property values for this paper are also listed in Table 3 for comparison.

Table 1 From Table 1, the cationized PVA according to the present invention is untreated P
Compared to VA, this shows that the strength of the paper quality is improved by using it as an internal additive in paper making. From this table, Example 4. The heterogeneous grafted cationized PVA as in Example 1. ．． 2. ．． It is interesting that the strength of the paper quality is almost the same as that of cationized PVA obtained by grafting with a uniformity of 3.0, and is significant from an industrial perspective.

Next, Table 2 shows Example 2. A comparison was made of the state of fixation of lateral carbonate to the pulp in paper making using cationized PVA and untreated PVA, and the results showed that cationized PVA had a much larger amount of fixation.

In Table 3, different bases, for example, polymerization degree 550,
Using a material with a saponification degree of 88.4 mol, cationized PVA was prepared by graft copolymerization, and the resulting cationized PVA was used to make paper in the same manner as above. This shows that there is almost no difference from the cationized PVA of the example. In this case, it has been shown that the degree of Steckigt sizing is particularly improved.

As described above, the cationized PVA according to the present invention has good binding to the pulp during beating during paper making, has a high retention rate of calcium carbonate especially on the side, and therefore has good freeness during filtration and is easy to treat white water. Enhancement of the strength of the resulting paper quality,
A product with improved size can be obtained, and it is simpler than the conventional method for producing cationized PVA, and the basic principle is that it is much easier to produce and can be supplied at a lower cost than the conventional method for producing cationized PVA. can.

In addition, the TJ-thionated PVA according to the present invention can be applied not only as an internal additive for paper making, but also as a surface sizing agent for paper, an antistatic agent, a flocculant for polymers, an emulsifier for emulsions, a paste for household use, etc. Be expected.

Patent applicant: Denki Kagaku Kogyo Co., Ltd. Agent Satoshi Wenzhou, patent attorney Same patent attorney Mikio Segawa

Claims (1)

[Scope of Claims] l) A papermaking sizing agent mainly comprising cationized polyvinyl alcohol obtained by graft copolymerizing aminoalkyl methacrylate or aminoalkyl acrylate with polyvinyl alcohol. 2) Aminoalkyl methacrylate or +X aminoalkyl acrylate is a cationic monomer R...H or methyl group R1...ethyl group or 2-oxypropyl group R:...
A sizing agent for paper making according to claim 1, characterized in that it contains a methyl group or an ethyl group X...an inorganic negative group. 3) The cationized polyvinyl alcohol is a paper sizing agent according to claim 1, wherein 10 mol% or less of a cationic monomer is grafted to the polyvinyl alcohol unit i&.