JPH01111093A - Composition for coating surface of paper and production of paper - Google Patents

Abstract

PURPOSE: To obtain the subject composition giving paper excellent in waterproof property and surface strength, suitable for a high-speed printing, and suitable for an offset printing and a gravure printing by including a specific modified PVA and a starch, etc. CONSTITUTION: This composition for a paper surface coating contains (A) a modified PVA containing a copolymerization unit expressed by the formula [R<1> to R<4> are each H or an alkyl; (n) is 0-2; (m) 1-3] (B) one or more kinds selected from a group of a starch, starch derivative (preferably an oxidized dextrin powder, a cationized dextrin powder), cellulose derivative (preferably a CMC), PVA and polyacrylamide. By coating the above composition to paper, drying and then heat-treating at 50-150 deg.C for 10 sec to 30 min, the objective paper is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a composition for coating the surface of paper that exhibits excellent effects in improving printability and water resistance of paper, and a method for manufacturing paper using the same. Regarding.

BACKGROUND OF THE INVENTION The development of printing technology in recent years has been remarkable, and as printing speeds and quality have increased, printing paper has come to be required to have higher performance.

For example, offset printing requires water resistance against dampening water, and gravure printing requires surface strength that can withstand high-speed rubbing by a printing roller or the like during printing.

Conventionally, surface coating agents aimed at increasing the surface strength of paper and improving its printability include starch, starch derivatives such as oxidized starch and cationized starch, and cellulose such as carboxymethyl cellulose (hereinafter abbreviated as CMC). Natural or synthetic water-soluble polymer compounds such as derivatives and anion-modified polyacrylamide are used, among which oxidized starch is most commonly used.

Problems to be Solved by the Invention However, in response to the recent demands for improved printing permeability and improved water resistance, paper coated with the above-mentioned surface coating agent has problems that occur as printing speeds increase. For example, printing troubles such as paper peeling due to insufficient surface strength of paper, and printing troubles such as ink bleeding due to insufficient water resistance are becoming more common.

Means for Solving the Problems In order to solve the above-mentioned problems, the inventors of the present invention, as a result of intensive studies, have developed a material that significantly improves printing permeability and water resistance, and is excellent not only for acidic paper but also for neutral paper. The present inventors have discovered a composition for coating the surface of paper that exhibits these effects, and have completed the present invention.

That is, the present invention provides: (a) a modified polyvinyl alcohol containing a copolymerized unit represented by the following general formula; The present invention provides a composition for coating the surface of paper, which is characterized by containing two or more types.

(In the formula, R,, R2, R3, and R4 represent a hydrogen atom or an alkyl group, n represents 0, 1 or 2, and m represents 1.2 or 3) In the above formula, R1, R2, R=, and R4 is preferably an alkyl group having 1 to 8 carbon atoms.

In addition, the present invention provides (al) a modified polyvinyl alcohol containing a copolymerized unit represented by the above general formula, and starch;
After drying the paper coated with a paper surface coating composition containing one or more selected from the group of starch derivatives, cellulose derivatives, polyvinyl alcohol, and polyacrylamide, 50 to 150'l:,10 The present invention provides a method for producing paper, which is characterized by heating for a period of seconds to 30 minutes.

The present invention also provides (a) a modified polyvinyl alcohol containing a copolymerized unit represented by the above general formula; The present invention provides a method for producing paper, which comprises applying a composition for surface coating of paper containing two or more of the above to paper to which aluminum sulfate has been internally added and/or coated.

Next, the present invention will be explained in detail.

The modified polyvinyl alcohol (hereinafter abbreviated as modified PVA) containing copolymerized units represented by the above general formula used in the present invention is R, R, I? Compounds in which R and R are lower alkyl groups are preferred. In addition, this modified PVA is polyvinyl alcohol containing an epoxy group (hereinafter abbreviated as PVA).
For example, it may be a modified PVA in which an epoxy group is introduced by etherification reaction of PVA with epichlorohydrin, or a monomer having an epoxy group such as allyl glycidyl ether and vinyl acetate may be used. Modified PVA that has been copolymerized and then saponified may be used, but modified PVA itself is easy to manufacture,
The latter copolymerization is more preferred in terms of stability.

In this case, the copolymer is vinyl alcohol (hereinafter referred to as V
A)・Allyl glycidyl ether copolymer, VA・
1-(3-butenyloxy)-2゜3-epoxypropane copolymer, VA・1-allyloxy-3,4-epoxybutane copolymer, VA・1-allyloxy-4,5-
Epoxybencune copolymer, VA・1-allyloxy-
3,4-epoxy-3-methylbutane copolymer, VA・
1-allyloxy-3,4-epoxypenkune copolymer, VA-1-allyloxy-3,4-epoxy-3-methylpentane coffi polymer, VA・1-allyloxy-
4,5-epoxy-4-methylpentane copolymer, VA
・1-allyloxy-4゜5-epoxyhexane copolymer, VA・1-allyloxy-4,5-epoxy-4-
Methylhexane copolymers, VA/methallyl-methylglycidyl ether copolymers, VA/methallyl-dimethylglycidyl ether copolymers, copolymers containing vinyl ester units (e.g. vinyl acetate units) as the third copolymer unit, etc. can be mentioned.

In addition to the epoxy group-containing hexamer and vinyl ester, the above copolymers also include those copolymerized with other copolymerizable components. For example, acrylic acid, methacrylic acid, maleic anhydride. , maleic acid, fumaric acid, itaconic acid, acrylamide, methacrylamide, dimethylaminoethyl methacrylate, acrylonitrile, styrene, α-methylstyrene, vinyltoluene, divinylbenzene, isobutylene, isobutylene oligomer and the like. The total amount of one or more of these components is 50 parts by weight or less, preferably 30 parts by weight or less, based on 100 parts by weight of the entire copolymer.

Furthermore, the degree of saponification of the modified PVA used in the present invention can be varied;
It is preferably selected from the range of 0 mol % and 0 to 30 mol % of vinyl ester units. Moreover, these modified PVAs can also be further chemically modified. For example, H in the presence of an acid catalyst
Reacts with 2O2 to form glycerol groups, NaHSO3, Na
Reaction with 2S03 produces a sulfonic acid group, reaction with an alkylamine, alkylamine hydrochloride, etc. produces a cationic group, (
POCj! 3 + dimethylformamide), formyloxy group when reacted with phosgene, chloroformyloxy group when reacted with alcohols, phenols, mercaptans, carbazoles, and pyrazoles, and β-hydroxyethylation when reacted with organic acids. Esterification by reaction, cyclization reaction with other cyano groups, isocyanate groups, ketone groups,
Examples include reaction with cyanuric acid.

There is no particular restriction on the degree of modification of the modified PVA used in the present invention with an epoxy compound, but in the case of a copolymer, the content of unsaturated epoxy monomer units is preferably selected from the range of 0.01 to 10 mol%. Regarding the molecular weight, if the molecular weight is too high, the viscosity of the coating solution will be affected, and if the molecular weight is too low, it will be unfavorable in terms of the printability improvement effect. Measured value at 25℃ and 60 revolutions per minute is 5-200
A centipoise, preferably 10 to 100 centipoise is suitable.

In the surface coating composition of the present invention, the content of modified pvA is preferably 20 to 80% by weight in terms of solid content. If this is less than 20%, the effect of improving printability and water resistance is is difficult to noticeably appear, and if it exceeds 80% by weight, the cost becomes too high.

The modified PVA of the present invention can impart excellent printability and water resistance to paper even when used alone as a surface coating agent for paper, but starch, starch derivatives (oxidized starch, esterified starch, etherified starch , enzyme-modified starch, pregelatinized starch, cationized starch, etc.), cellulose 8M4 (CMC, hydroxyethyl cellulose, hydroxypropyl cellulose, etc.), PVA, NIJ acrylamide, etc. Not only can the printability and water resistance of the paper be improved more significantly than when each of them is used alone, but also the cost can be significantly reduced.

In particular, starch derivatives such as oxidized starch and cationized starch are preferred.

The paper coating composition of the present invention includes a water resistance agent, a thickener, a thinner, an antifoaming agent, a foam inhibitor, a preservative, an antifungal agent, a water retention agent, a fluorescence enhancer, and other components as mentioned above. Various auxiliary agents such as whitening agents, dyes, and conductive agents can also be blended as needed.

In order to produce the paper coating composition of the present invention, a modified PVA melt is prepared, as well as an aqueous solution of the above-mentioned starch and the like, and these are mixed. Additionally, other auxiliary agents may be added as necessary. Then, if necessary, the pH is adjusted with caustic soda or the like to complete the process.

The paper coating composition of the present invention is coated onto a base paper by a conventionally known method. That is, it is preferable to use a size press, a scale coater, a blade coater, or a calender. Coating may be performed using a commonly used method such as a knife coater, air knife coater, bar coater, roll coater, etc., and may be either on-machine coating or off-machine coating, or may be -layer coating. It may also be multilayer coating, and furthermore, either single-sided coating or double-sided coating is possible.

After coating the surface coating composition of the present invention, it is preferable to heat-treat the coated paper at the same time as or after drying in order to improve the printability and water resistance of the paper. Although it depends on the amount and type of base paper, it is preferable that the actual ship thermal temperature is 50 to 150°C and the heating time is 10 seconds to 30 minutes.

When the temperature is lower than this range or for a short time, the above effect is not as pronounced as when it is within this range, and when the temperature is higher than this range or for a long time, the effect on the energy cost ratio is not increased. For example, a gas heater,
An electric heater, a steam heater, a hot air heater, etc. are used, and after drying, a super calender etc. can be used depending on the lφ method, and any other processing means such as boat fishing can be used.

The surface coating composition of the present invention further improves the printing permeability and water resistance by being coated on coated paper that has been internally added and/or coated with an aluminum sulfate aqueous solution before the coating process. can be improved.

The amount of aluminum sulfate is 0.5 to 3.0% based on the bulb amount in case of internal addition, and 1.0 to 1.0% in case of coating amount.
5 g/m is preferred.

The paper coated with the coating composition according to the invention has particularly good surface strength.
Furthermore, it has excellent water resistance and can produce beautiful printed matter.

EXAMPLES Next, the present invention will be explained based on Examples, but it goes without saying that the present invention is not limited to these Examples.

Example 1 First, modified PVA is synthesized as follows.

Slurry obtained by adding allyl glycidyl ether as an epoxy group-containing monomer at 3% to vinyl acetate monomer, making a solution with methanol, and then carrying out tax monomer and saponification reaction according to the usual method. was dried to obtain modified PVA 1. The specific contents of this resin are shown in Table 1.

The specific manufacturing method for this modified PVA 1 is disclosed in Japanese Patent Application Laid-open No. 6
The method described in Japanese Patent No. 0-195103 was used. That is, the 0 polymerization temperature at which polymerization was carried out by a solution polymerization method using methanol using 2,2''-azobisisobutyronitrile as a catalyst was taken as the boiling point.

Next, methanol vapor is added to the polymerized paste.

After blowing the tax monomer, a saponification reaction is carried out using a Nigu using a sodium hydroxide solution as a catalyst to produce modified PV.
I got A1.

Next, an aqueous solution of modified PVA 1 and oxidized starch (manufactured by Tamago Cornstarch ■, trade name Tamago Ace A) which had been subjected to a cooking process in advance were mixed in the proportions shown in Table 2 below. The prepared coating solution was coated on the following acidic high-quality paper under the following conditions so that the coating amount was 0.3 g/rd and dried, and the surface strength of the obtained paper was measured under the following conditions.

■ Paper used: High-quality paper made under acidic conditions without surface treatment, with the following specifications.

Valve: Bleached craft valve softwood/hardwood - 3/7 Basis weight: 65g/n? Paper filling amount: Talc 14% (internally added chemicals) Sulfate band: 1.5% Rosin size: 0.1% Steckigt sizing degree of base paper: 1.5 seconds■ Size press equipment for coating and drying tests (Kumagaya) (manufactured by Riki Kogyo Co., Ltd.) for double-sided coating with a tube pressure of 20 kg/am and a coating speed of 100 m.
/win, coating temperature 60°C) and dried with a drum dryer at 80°C for 50 seconds. After drying 20℃, 65
After being left in a constant temperature and humidity chamber at %RH for 24 hours, it was subjected to a test.

■ Measurement conditions Surface strength Nidry Pink R1 printing tester, nip IfilO Tsuru ink, FINE INK, (Dainippon Ink Chemical Industries, Ltd., for IGT printing passability test) T, V 16 Wetpick RI printing tester, nip @10Tsuru , using Molton roll, ink; CAPS G (manufactured by Dainippon Ink Chemical Industry Co., Ltd.,
For offset) T and V8, the paper peeling condition after printing was observed with the naked eye and evaluated on a five-point scale, with 5 being excellent and l being poor.The results are shown in Table 2.
show.

Comparative Example I The coating liquid of the comparative example shown in Table 2 using unmodified PVA instead of PVAI was applied to high-quality paper in the same manner as above, and the evaluation results are shown in Table 2.

! ! ! (The 1 juice used for each sample is also ~ A's V silicon (viscosity promotion condition = ν further (purtsukfir n camellia if - 1 m
25°C, unit weight → Table 2 Example 2-IO Modified PVAOMIM was replaced with modified PVAOMIM in the same manner as in Example 1 except that the corresponding monomers shown in R1 were added in the corresponding amounts to vinyl acetate.
VAs 2 to 9 were synthesized and evaluated in the same manner as in Example 1, except that each of them and PvAl was used. The results are shown in Table 3.

Table 3 Examples 11 to 14 Modified PVA 1 and pre-dissolved cationized starch (commercial product for size press) (Example 11), CMC (commercial product with a 1% solution viscosity of 80 cps at 25°C) (Example 12)
), PVA (unmodified) (Example 13), or polyacrylamide (anion-modified commercial product for size press) (Example 14) was mixed with a solution of modified PVA l of 0.2 g/
rd, each of the above water-soluble polymer compounds is 0.1 g/
rr? The coating solution was mixed and adjusted so as to have a coating amount of , and was coated on high-quality paper under the same conditions as in Example 1, and its surface strength was measured. The results are shown in Table 4.

Comparative Examples 2 to 6 The same procedure as Example 1 was carried out, except that the solutions of the water-soluble polymer compounds used in Examples 2 and 11-14 were applied at a coating amount of 0.3 g/rd. The results are shown in Table 4.

Table 4 Examples 15 to 16 The surface of the same base paper as in Example 1 was coated with 0.7 g/m of aluminum sulfate using a bar coater, and then dried using a drum dryer (80°C,
50 seconds). Each of the surface coating compositions shown in Table 5 prepared using modified PvA1 and unmodified PVA was applied to this base paper in the same manner as in Example 1 and evaluated. Note that Comparative Example 7 shown in Table 5 does not use modified PVA 1.
Table 5 shows the results of evaluation using coating solution No. 8 in the same manner.

Table 5 shows that pretreatment with aluminum sulfate improves the surface strength when modified PVA 1 is used.

Table 5 Examples 17-18 Modified PVA and oxidized starch were coated on the surface in the same manner as in Example 1, and then heat treatment was performed as shown in Table 6. The evaluation results are shown in Table 6.

From Table 6, it was found that in the case of modified PVA 1, the surface strength was improved by heat treatment.

Table 6 Effects of the Invention According to the present invention, since a modified PVA having an epoxy group and a water-soluble polymer such as starch are used together in the paper surface coating composition, the water resistance and surface strength of the paper are significantly improved. , it is possible to provide paper that can be subjected to high-speed printing, and it can also be printed beautifully, making it suitable for offset printing and gravure printing.

October 22, 1985 Patent applicant: Dick Vercules Co., Ltd. Procedural Report 1) November 9, 1988 Patent Office Commissioner Kunio Ogawa 2 Name of the invention Composition for surface coating of paper Manufacturing method for products and paper 3, relationship with the amended person case Patent applicant: 3-7-20 Nihonbashi, Chuo-ku, Tokyo Representative: Dick Vercules Co., Ltd. - 1-4 Yurakucho, Chiyoda-ku, Tokyo No. 1 Denki Kagaku Kogyo Co., Ltd. Representative Akira Shinohara 4, Agent ■105 Miki Building 6, 2-2-10 Nishi-Shinbashi, Minato-ku, Tokyo Number of inventions increased by amendment None 7. Subject of amendment "Description "Detailed Description of the Invention Column" 8. Contents of Amendment (1) In the 9th line of page 7 of the specification, the words "rR, RSR and R" are corrected to rRl, R2, R3 and R4J.

(2) On page 13, line 16 of the specification, "coated paper" is corrected to "paper."

(3) On page 13, lines 19 and 20 of the specification, it is stated that ``In the case of coating amount, 1.0 to 1.5 g/rrrJ'' is replaced with ``
In the case of coating, it is corrected to 0.1 to 1.5 g/rd J.

(4) In the specification, page 16, line 16, and page 17, line 1, rT, V J are corrected to "T, ν," respectively.

(5) In the third and second lines from the bottom of page 19 of the specification, rP
The text “VA I J” has been corrected to “Modified PVA I J.”

(6) Table 2 on page 19 of the specification, Table 3 on page 20, Table 22
Below the margins of Table 4 on page 23, Table 5 on page 23, and Table 6 on page 24, add ``In the tables, the units of composition indicate parts by weight.''

Procedural amendment iF (spontaneous) August 12, 1988 Director General of the Japan Patent Office Yoshi 1) Takeshi Moon 1, Indication of the case 1988 Patent Application No. 265474 2, Name of the invention Composition for coating the surface of paper and paper Manufacturing method 3, relationship with the case of the person making the amendment Patent applicant: 3-7-20 Nihonbashi, Chuo-ku, Tokyo Representative: Dick Vercules Co., Ltd. - 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Electric Co., Ltd. Representative of Kagaku Kogyo Co., Ltd. Akira Shinohara 4, Agent ■105 5. Date of amendment order Voluntary 6. Subject of amendment "Column for detailed explanation of the invention in the memo" 7. ? ! Positive contents (1) In the fourth line under the chemical formula on page 6 of the specification, rR+, R
z, R3 and R4 are the number of carbon atoms r Rt % R
z, R3 and the group are hydrogen atoms or carbon numbers.''

(2) On page 7, lines 9 and 10 of the specification, "R'
, RZSR3 and R+ are lower alkyl groups," should be corrected to read, "rR+SRz, Rh and R+ are hydrogen atoms or lower alkyl groups."

(3) On page 14, line 11 of the specification, It says "3%", Correct it to "3 mol%."

(4) In lines 8 and 9 of page 15 of the specification, the words "mixed" should be corrected to "mixed."

(5) The ``-'' in the amount of modification (mol %) in the sixth column from the left of the Example 5 column in Table 1 on page 18 of the specification is corrected to ``3''.

Claims (6)

[Claims] (1) (a) modified polyvinyl alcohol containing a copolymerized unit represented by the following general formula; and (b) one or two selected from the group of starch, starch derivatives, cellulose derivatives, polyvinyl alcohol, and polyacrylamide. A composition for coating the surface of paper, characterized by containing the above. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1, R_2, R_3 and R_4 are hydrogen atoms or alkyl groups, n is 0, 1 or 2, m is 1, 2 or 3) (2) The composition for coating the surface of paper according to claim 1, wherein the starch derivative is oxidized starch. (3) The composition for coating the surface of paper according to claim 1, wherein the starch derivative is cationized starch. (4) The paper surface coating composition according to claim 1, wherein the cellulose derivative is carboxymethylcellose. (5) (a) modified polyvinyl alcohol containing a copolymerized unit represented by the following general formula; and (b) one or two selected from the group of starch, starch derivatives, cellulose derivatives, polyvinyl alcohol, and polyacrylamide. A method for producing paper, which comprises drying the paper coated with a paper surface coating composition containing the above and then further heat-treating the paper at 50 to 150°C for 10 seconds to 30 minutes. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1, R_2, R_3 and R_4 are hydrogen atoms or alkyl groups, n is 0, 1 or 2, m is 1, 2 or 3) (6) (a) modified polyvinyl alcohol containing a copolymerized unit represented by the following general formula; and (b) one or two selected from the group of starch, starch derivatives, cellulose derivatives, polyvinyl alcohol, and polyacrylamide. A method for producing paper, which comprises applying a composition for surface coating of paper containing the above to paper to which aluminum sulfate has been internally added and/or coated. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1, R_2, R_3 and R_4 are hydrogen atoms or alkyl groups, n is 0, 1 or 2, m is 1, 2 or 3)