JPS61207697A - Surface processing agent of paper - 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 [Industrial Application Field] The present invention is a paper surface treatment that can be applied to the surface of paper to improve the paper's dry and wet surface strength, barrier properties against solvents, water resistance, and sizing properties. This is related to drugs.

[Conventional technology]

Conventionally, in order to improve the surface strength of paper, a method has been adopted in which starch, polyvinyl alcohol (hereinafter referred to as PVA), or polyacrylamide (hereinafter referred to as PAM) is applied or impregnated onto paper through secondary processing such as size pressing. However, in general, materials with excellent surface strength and barrier properties tend to have poor water resistance, and materials with excellent water resistance tend to have poor surface strength and /4 barrier properties, each having advantages and disadvantages of 1. For example starch, PVA%PA
Although N and the like mainly impart surface strength and barrier properties, the extent of these effects is not sufficient, and there is no improvement in water resistance. Furthermore, commercially available synthetic surface sizing agents containing styrene are effective in improving the water resistance of coated paper, but cannot provide sufficient surface strength or barrier properties.

[Problem that the invention seeks to solve]

The present invention seeks to provide a paper surface treatment agent that improves water resistance, barrier properties, dry and wet surface strength and sizing.

[Means for solving problems]

That is, the surface treatment agent of the present invention is a paper material made by adding glyoxal to a water-soluble polymer containing PAM t or a derivative thereof as a main component, a copolymer of styrene and acrylic acid ester monomers using the compound as a protective colloid. It is a surface finishing agent.

When emulsion polymerizing styrene and acrylic acid ester monomers, the surface treatment agent of the present invention may be used as an appropriate surfactant, but in particular nonionic, anionic, or amphoteric PAM may be used as a protective colloid. can be used.

That is, an acrylic ester copolymerizable with styrene is added to a solution of PAM or its derivative at an appropriate concentration, emulsified and dispersed, a polymerization initiator is added, emulsion polymerization is performed, and then glyoxal (hereinafter referred to as GX) is added. By this process, the paper surface finishing agent of the present invention can be obtained.

The amount of each component of the paper surface finishing agent according to the present invention is determined by the resin content.
Preferred ranges are 10 to 80% by weight of AMt or its derivatives, 20 to 80% by weight of styrene + acrylic ester, 10 to 40% by weight of acrylic ester of styrene, and 2 to 30% by weight of glyoxal. .

Here, PAM or its derivative is an essential component for emulsifying styrene and acrylic acid ester, which are hydrophobic substances, and if the amount used is less than 10% by weight, coagulation may occur in the emulsion. , or the stability of the resulting emulsion deteriorates. If it exceeds 80% by weight, the stability of the resulting emulsion solution will improve, but the size effect will worsen.

In addition, if the total amount of styrene and acrylic ester is less than 20% by weight, the development of sizing will be slow and there will be no economic advantage.If it exceeds 80% by weight, coagulation will occur in the emulsion or the emulsion will become unstable The properties are also poor, and the barrier properties against solvents are also insufficient.

Furthermore, if the amount of acrylic ester is less than 10% of styrene or more than 40% by weight, the size effect will be extremely poor.

Furthermore, if the glyoxal content is less than 2% by weight, the water resistance and surface hardness will be insufficient, and if it exceeds 30% by weight, the storage stability of the emulsion will be poor. PAM or its derivatives used as protective colloids are nonionic, cationic, anionic, or even amphoteric, consisting of acrylamide, methacrylamide, acrylic acid, methacrylic acid, dimethylaminodiethyl methacrylate/epichlorohydrin nitrate, etc. as monomer components. Although any of them can be used, cationic PAM is preferred in order to provide stable effects over a wide vocal range.

It is also possible to exhibit the effect of a protective colloid while simultaneously polymerizing the monomer component of PAM or its derivative during emulsion polymerization.

The acrylic ester to be copolymerized with styrene is represented by the general formula %, where n is an integer of 1 or more, but is particularly preferably 4 to 6 in order to sufficiently exhibit the size effect.

The paper surface finishing agent of the present invention can be used alone or in combination with other surface finishing agents such as starch or PVA. The paper surface finishing agent of the present invention is a size press,
It is applied to the surface of paper using various processing devices such as tag size, carrier/dar coating, roll coater, spray coating, etc., and is used to determine the printability of paper, mainly offset printability, and barrier properties against solvents. , improve water resistance, sizing, dry and wet tensile strength, etc.

In addition, the paper surface finishing agent of the present invention can be applied to both sized paper and non-sized paper, as well as water-soluble binders used in coated paper and thermal paper covers, such as modified starches such as oxidized starch, and phosphorus. Mixed with natural or synthetic water-soluble polymers such as starch derivatives such as acid-modified starch, gelatin, calxymethylcellulose, hydroxyethylcellulose, hydroxyglobilcellulose, methylcellulose, gum arabic, sodium alginate, privinylpyrrolidone, PVA, and PAM. By using it, the binder effect and water resistance can be significantly improved.

Furthermore, the effect is significantly improved when used as a substitute for various latexes and water-soluble polymers used as water-soluble binders in the size layer of offset master base paper.

The present invention will be explained below with reference to production examples and test examples, but the following description is not intended to limit the present invention.

Reference Example 1 420m/ml of water and 100ml of Inglobil alcohol were added to an 11-4 solo flask equipped with a Thumb funnel, stirrer, thermometer, and dropping funnel. F. Add 5 g of acrylamide 959 methylaminoethyl methacrylate epichlorohydrin nitrate, mix and dissolve, and add IN-nitric acid to P) I3. Adjusted to O. Next, the temperature was raised to 50° C. in nitrogen, and 0.59 ammonium persulfate dissolved in 40 grams of water was gradually added dropwise, followed by reaction at 60° C. for 2 hours. pH? , Gardner viscosity H,I.

A cationic preacrylamide solution with a solid content of approximately 6
60g was obtained.

Reference Example 2 Using the same apparatus as in Reference Example 1, an amphoteric polyamide with a pH of 5 and a Gardner viscosity of H1 of 15% solids was prepared using the same procedure as in Reference Example 1, except that 93 g of acrylamide, 2 g of acrylic acid, and 5 g of dimethylaminoethyl methacrylate/epichlorohydrin nitrate were used. Approximately 660 p of acrylamide solution was obtained.

Example 1 A device similar to Reference Example 1 was charged with 223 g of deionized water, 15 g of styrene, 15J7 (butyl acrylate), 367 g of the cationic PAM 15J7 solution produced in Reference Example 1, and 0.03 g of ammonium persulfate, and then heated with nitrogen. Medium 70℃
After reacting for 2 hours at 90°C, the mixture was further reacted for 4 hours. Next, 325 g of 40% glyoxal was added dropwise for 10
After reacting for minutes and cooling to 30°C, the pH was 14 and the viscosity was 1.
Approximately 6531 15% emulsions of 20 cps1 (25°C) were obtained.

Example 2 In a device similar to Reference Example 1, 400 g of deionized water, styrene (409.2-ethylhexyl acrylate) 25,
L 15% solution 2 of zwitterionic PAM prepared in Example 2
00I and 0.19 ammonium persulfate were charged and reacted in nitrogen at 70°C for 2 hours, and then further reacted at 90°C for 6 hours. Then 40 tiglyoxal IL51I
was added dropwise, reacted for 10 minutes, cooled at 30'C1,
pH 3.3, viscosity 13 Q cps (25°C) 15
Approximately 667 y of emulsion was obtained.

Example 3 Add 2 g of deionized water to the same apparatus as in Reference Example 1.

Styrene 14! j% Butyl acrylate 10g, acrylic acid 1.6p, acrylamide 40g, dimethylaminoethyl methacrylate epichlorohydrin nitrate 4g
, ammonium persulfate 0.4Ii and sodium dodecylbenzenesulfonate 2,9t-charge at 90°C.
After reacting for an hour, 26 g of 40% glyoxal was added and reacted for 60 minutes, pH 3.4, viscosity 20 cps.
Approximately soog of 10% emulsion (at 25° C.) was obtained.

Comparative Example 1 In the same apparatus as Reference Example 1, 840 g of deionized and 5 styrene were added.
0g, butyl acrylate 32L 15% solution of cationic PAM prepared in Reference Example 1 539 and ammonium persulfate 0.051i were charged and reacted in nitrogen at 70°C for 2 hours and at 90°C for 1 hour, resulting in condensation in the reactor. The reaction was stopped because many lumps were generated.

Comparative Example 2 A device similar to Reference Example 1 was charged with 775 g of deionized water, 6 g of styrene, 567 g of the cationic PAMC) 15% solution prepared in Example 1, and 0.02 II of ammonium persulfate, and nitrogen gas was added. 2 hours at 70°C and 2 hours at 90°C, then 4 hours.
125 g of 0% glyoxal was added, reacted for 10 minutes, and cooled to 30°C. pH&O, viscosity 110 cps
Approximately 667 g of 15% emulsion (at 25° C.) was obtained.

Comparative Example 3 In a device similar to Reference Example 1, 223 g of deionized water and 28 g of styrene were added. i, Butyl acrylate 2L cationic PAM
367 g of a 15% solution of and 0.0 ammonium persulfate
In the same manner as in Example 3, except that 3J was charged, about 5sa9 of -3.4C was obtained with a viscosity of 110 cps (25 DEG C.).

Comparative Example 4 Into the same apparatus as in Reference Example 1, 284 g of deionized water, styrene ASII, butyl acrylate (15 F%), 333 g of the 15% solution of cationic PAM prepared in Reference Example 1, and o, o a g of ammonium persulfate were charged. React in nitrogen for 2 hours at 70°C and 3 hours at 90°C to adjust pH & o.
, a 15% emulsion with a viscosity of 100 cps (at 25°C), approximately 667 Ft.

Comparative Example 5 Into the same apparatus as in Reference Example 1, 337 g of deionized water, styrene 20J1 butyl acrylate) 10,9. 200 g of the 15% solution of cationic PAM produced in Reference Example 1 and 0.039 ammonium persulfate were charged, and the mixture was heated at 70°C in nitrogen for 2 hours.
React for 3 hours at 90°C, then add 100g of 40% glyoxal and react for 10 minutes.
Cooled at Ct. -3,4 viscosity 1000aps (25
Approximately 6,671 pieces of 15% emulsion (15%) were obtained, but when left for one day, they turned into liquid.

Test Example 1 Application to Size Press The emulsions of Examples 1 to 3 and Comparative Examples 2 to 4 and commercially available polyvinyl alcohol or oxidized starch were used as paper surface finishing agents, respectively.

A diluted solution with a solid content of 1.0% was prepared, size-pressed onto high-quality paper, and then dried for 3 minutes with a drum dryer at 100° C. to obtain processed paper. The results of measuring various strengths of processed paper are shown in the table below.

The paper strength test method was conducted under the following conditions.

■IGT printing suitability Using IGT printing aptitude tester Spring Drive A1 printing pressure 5oklI.

The ink used was from Dainippon Ink Co., Ltd., and the tack value 9 results are shown in printing speed (Den^ee). The larger the number, the higher the surface strength.

■RI Test Using RI Printing Aptitude Tester The ink used was Dainippon Ink Co., Ltd., and the tack value 9 results were evaluated as follows.

A: f, no kinging (fiber peeling) B: slight picking C: a lot of picking ■Wet Rub test Test with a rotating grindstone (GC 60*50 rpm + the lower end is in contact with water, so it's always wet) Abrasion resistance is determined by rubbing the surface of the piece.

It is expressed as the time until the test piece breaks due to wear.

(2) Solvent barrier property A test piece is placed on a plate inclined at 45 degrees, and one drop (approximately 0.025 M) of toluene is dropped from the top and bottom, and the solvent barrier property is observed from the falling state.

The results were evaluated as follows.

○: Has barrier properties Δ: Slightly present ×: None ■Steckicht size test This was done in accordance with JIS P8122.

Claims (1)

[Claims] A paper surface treatment agent made by adding glyoxal to a copolymer of styrene and acrylic acid ester monomers with a water-soluble polymer compound mainly composed of polyacrylamide or its derivative as a protective colloid.