JPS6237160B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for treating paper by methods such as impregnation and coating. Improve paper size, paper surface strength,
In order to improve oil resistance, smoothness, etc., it is known to treat paper with an aqueous polyvinyl alcohol solution by means such as impregnation or coating. However, when the paper subjected to such treatment is dried by passing it between rolls in the next step, there is a problem that the dryer roll, canvas, and calender roll gradually become dirty, and the dirt gradually accumulates. This dirt damages the surface properties of the paper and degrades the quality of the paper, so the roll surface must be cleaned from time to time. However, in high-speed machines, stopping the machine from time to time to clean the roll surface is so disadvantageous as to be fatal to productivity. Some things are beyond dispute. However, in order to deal with this problem, methods have been proposed in which additives such as polyhydric alcohol, paraffin emulsion, anionic surfactant, nonionic surfactant, urea, etc. are added to the polyvinyl alcohol aqueous solution, but the effect is Not necessarily enough. However, the present inventor has conducted intensive research to solve the above-mentioned conventional problems, and as a result, when a higher aliphatic amine and a dispersant for the amine are made to coexist in an aqueous solution containing polyvinyl alcohol as a main ingredient, The inventors discovered that even if paper treated with an aqueous solution is fed between a group of rolls, stains do not occur on the roll surface for a long period of time, leading to the completion of the present invention. As the polyvinyl alcohol in the present invention, polyvinyl alcohol with a degree of polymerization of 300 to 3000 is used, but depending on the purpose, polyvinyl alcohol with an extremely low degree of polymerization of about 50 to 300 can also be used. The degree of saponification of polyvinyl alcohol is approximately 40
A mol% to 100 mol% is used. Among these, those with a relatively low degree of saponification do not necessarily have sufficient water solubility, but if used in combination with an organic solvent or an anionic surfactant as a dispersant described later, uniform dissolution is possible, so they are particularly suitable for use. There is no problem. The polyvinyl alcohol in the present invention also includes so-called modified polyvinyl alcohol. Examples of the modified polyvinyl alcohol include saponified copolymers of vinyl acetate and a comonomer copolymerizable with vinyl acetate. Comonomers include vinyl esters other than vinyl acetate (for example, vinyl propionate, vinyl stearate, vinyl benzoate, vinyl saturated branched fatty acids, etc.), unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, or alkyl esters thereof. , maleic acid, maleic anhydride, fumaric acid,
Unsaturated polyhydric carboxylic acids such as itaconic acid or their partial or complete esters, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, olefin sulfonic acids (e.g. ethylene sulfonic acid, allyl sulfonic acid, methalylsulfonic acid, etc.) or the salt,
Ethylene, propylene, butene, α-octene,
Examples include α-olefins such as α-dodecene and α-octadecene, and vinyl ethers. The proportion of these comonomers in the copolymer is less than 20 mol %, preferably less than 10 mol %. Another group of modified polyvinyl alcohols are post-modified products of saponified homopolymers or copolymers of vinyl acetate as described above. Examples of post-modification include acetalization, urethanization, phosphoric acid esterification, sulfuric acid esterification, and sulfonic acid esterification. The concentration of the polyvinyl alcohol aqueous solution is not particularly limited, but is usually selected from a range of about 0.1 to 10% by weight. In addition to polyvinyl alcohol, other polymer components such as starch, modified starch, dextrin, acrylamide polymer, cellulose polymer, etc.
There is no particular problem in using polymer latex or the like up to the same weight level. The aqueous solution may contain a small amount of a water-miscible organic solvent. Now, examples of higher aliphatic amines used in the present invention include amines represented by the formulas RNH ₂ , R ₁ R ₂ NH, R ₁ R ₂ R ₃ N, and RNH(CH ₂ ) ₃ NH ₂ (herein, R,
R ₁ , R ₂ , and R ₃ are aliphatic saturated or unsaturated hydrocarbon groups having 8 to 20 carbon atoms), especially monoalkylamine represented by RNH ₂ , alkyl represented by RNH(CH ₂ ) ₃ NH ₂ Propylene diamine is preferred. These amines may be used alone or in combination of two or more. The amount of the above amine used is 0.01 to 10% by weight, preferably 0.1 to 5% by weight based on polyvinyl alcohol.
It is desirable to do so. If the amount is too small, the effect of preventing stains on the roll will be poor, while if it is too large, sizeability, printability, strength, etc. may be impaired, so it should be avoided. Next, an anionic surfactant, a nonionic surfactant, a cationic surfactant, and a polyhydric alcohol are used as the dispersant for the amine. Specific examples include anionic surfactants such as higher alcohol sulfates, fatty acid salts, alkylbenzene sulfonates, alkylnaphthalene sulfonates, polyoxyethylene alkyl phosphates, alkyl phosphate ester salts, and dialkyl sulfone succinates. Nonionic surfactants: polyoxyethylene alkyl ether with HLB7 or higher, polyoxyethylene alkyl phenol ether, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, sorbitan ester, polyoxyethylene sorbitan ester, glycerin mono Alkyl esters, polyoxyethylene alkylphenol formaldehyde condensates, polyoxyethylene-polyoxypropylene block copolymers, and other polyoxyethylene derivatives. Cationic surfactants: various quaternary ammonium salts, etc. Polyhydric alcohol: ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, diglycerin, 3-methylpentane-1,3,5-triol, etc. One or more types of these dispersants may be used.
The amount of dispersant used is preferably 1 to 500% by weight based on the amine in the case of a surfactant, and 10 to 5000% by weight based on the amine in the case of a polyhydric alcohol. If the amount is too small, it will be difficult for the amine to be uniformly dispersed in water, while if it is too large, the sizing of the paper will decrease and the strength imparted by polyvinyl alcohol will be diminished. Aqueous solution containing polyvinyl alcohol, higher aliphatic amine, and dispersant (may also contain other additives, such as polymers other than polyvinyl alcohol, latex, fillers, pigments, dyes, waterproofing agents, rust inhibitors, etc.) ) is used to process the paper. Examples of the treatment include size press coating and surface coating using a calender roll. Next, the method of the present invention will be further explained with reference to Examples. Hereinafter, "parts" and "%" are expressed on a weight basis unless otherwise specified. Example 1 One part of an ethylene oxide and propylene oxide adduct of ethylenediamine was added as a dispersant to one part of monostearylamine, and 98 parts of water was added thereto and the mixture was heated and stirred to obtain a dispersion. Add 3 parts of the above dispersion to 3 parts of polyvinyl alcohol with a degree of polymerization of 1700 and a degree of saponification of 99.0 mol% (the amount of amine relative to the polyvinyl alcohol is 1.0%), add 94 parts of water to this, and heat and stir. Polyvinyl alcohol was completely dissolved. Using a Dickson coater, the above aqueous solution was coated on the surface of a corrugated board liner at 10 g/m ² on a wet basis by the bar coating method, and then coated on an iron heating roll (temperature 110°C) with an outer diameter of 10 cm at a speed of 3 m/min. were brought into continuous contact. As shown in Table 16
Almost no staining of the roll was observed even after hours of continuous operation. The surface condition of the coated and dried paper was also very favorable as shown in Table 1. Control example 1 3% of polyvinyl alcohol used in Example 1
When applying using only an aqueous solution and then passing the paper through a heated roll, the roll was considerably stained after 30 minutes. Comparative Example 2 Even when monostearylamine alone was not used in Example 1, that is, when an aqueous solution containing only polyvinyl alcohol and a dispersant was used for coating and passing the paper through a heated roll, the stain on the roll was noticeable. Control Examples 3 to 6 Polyvinyl alcohol 3 used in Example 1
% aqueous solution was prepared, and polyoxyethylene lauryl ether with HLB 10.5 (Comparative Example 3), polyoxyethylene nonylphenol ether with HLB 10.8 (Comparative Example 4), and polyvinyl alcohol were added in an amount of 1% based on polyvinyl alcohol. Add 10% glycerin (Control Example 5) or polyvinyl alcohol to 10% urea and 5% polyoxyethylene nonylphenol ether (Control Example 6), apply this aqueous solution, and pass the paper through a heated roll. I did it. The results of the above Control Examples 1 to 6 are also shown in Table 1.

【table】

[Table] Examples 2 to 5 Experiments were conducted using the following combinations of amines and dispersants. The amount of amine used was 1% relative to polyvinyl alcohol. Example 2 Monostearylamine 1 part Polyoxyethylene derivative (Kao Soap Co., Ltd. Emulgen A-60, HLB12.8) 1 part Example 3 Monostearylamine 1 part Diethylene glycol 9 parts Example 4 Stearylpropylene diamine 1 part Ethylene diamine Oxide and propylene oxide adduct 1 part Example 5 Stearylpropylene diamine 1 part Triethylene glycol 9 parts The results are shown in Table 2.

[Table] Example 6, Comparative Example 7 9 parts of triethylene glycol as a dispersant was added to 1 part of stearylpropylene diamine, and the mixture was heated and stirred to obtain a mixture that was in the form of a solution at high temperatures and in the form of a paste at room temperature. Add 3 parts of the above mixture to 1000 parts of a 3% aqueous solution of a saponified product obtained by saponifying 95 mol% of the vinyl acetate component of a monomethyl maleate-vinyl acetate copolymer with a monomethyl maleate content of 3.0 mol% (an amine relative to modified polyvinyl alcohol). (the amount of 1%) was heated and stirred to prepare a homogeneous aqueous solution. Using a Dixon coater, the above aqueous solution was coated on the surface of a corrugated board liner at a wet weight of 10 g/m ² using a bar coating method, and then coated on an iron heating roll (temperature 110°C) with an outer diameter of 10 cm at a rate of 3 m/min. Continuous contact was made at speed. As a control example, a comparative experiment was also conducted in which only the addition of amine was omitted. Control example 7 Examples 7 to 9, Control examples 8 to 10 Saponified sodium allyl sulfonate-vinyl acetate copolymer with a sodium allyl sulfonate content of 0.5 mol% and a saponification degree of vinyl acetate component of 99.4 mol% as polyvinyl alcohol. (Example 7), a saponified product obtained by saponifying 99.3 mol% of the vinyl acetate component of a crotonic acid-vinyl acetate copolymer with a crotonic acid content of 1.0 mol% (Example 8), an acrylic acid content of 5 mol%
The paper surface size was measured in the same manner as in Example 6, except that a saponified product (Example 9) in which 99.7 mol % of the vinyl acetate component of the acrylic acid-vinyl acetate copolymer was saponified was used. As a control example, a comparative experiment was also conducted in which only the addition of amine was omitted.
(Comparative Examples 8, 9, and 10 in this order.) The results of Examples 6 to 9 and Comparative Examples 7 to 10 are summarized in the third
Shown in the table.

【table】

Claims (1)

[Scope of Claims] 1. A method for treating paper, which comprises treating paper using an aqueous solution containing polyvinyl alcohol as a main ingredient, and comprising coexisting a higher aliphatic amine and a dispersant thereof in the aqueous solution. 2. The method according to claim 1, wherein the dispersant is a surfactant. 3. The method according to claim 1, wherein the dispersant is a polyhydric alcohol. 4. The method according to claim 1, wherein the amount of higher aliphatic amine used is 0.01 to 10% by weight based on the polyvinyl alcohol. 5. The method according to claim 1, wherein the amount of higher aliphatic amine used is 0.1 to 5% by weight based on the polyvinyl alcohol.