JPS5927974A - Paper adhesive - Google Patents

Abstract

PURPOSE:To provide a paper adhesive with excellent dispersion stability and improved bonding workability, by incorporating a particular vinyl polymer emulsion and a starch-based compd. CONSTITUTION:A vinyl monomer (e.g., vinyl acetate) is subjected to emulsion polymn. in water in the presence of a nonionic surfactant (e.g., polyoxyethylene alkyl ether), a water-soluble high-molecular compd. (e.g. PVA), and a catalyst (e.g., potassium persulfate) to yield a vinyl polymer emulsion with a particle size of 0.1-1.5mu and a zeta-potential of 4-40(-mV). Then 70-90wt% said emulsion and 10-30wt% starch-based compd. (e.g., raw starch) are mixed together.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides adhesive 5'aA, which uses a starch-based compound in combination with a paper vinyl polymer emulsion that has significantly improved adhesive workability.
It is related to U.

Conventional adhesives containing starch compounds for paper use storage #i, Iυ
Because starch-based compounds precipitate during the process, dispersion during use is essential in order to maintain the desired adhesion performance, and when stored for a long period of time, they will significantly precipitate and solidify, so dispersion during use is essential. The work was extremely difficult.

Therefore, there was a problem that stable adhesive performance could not be obtained.

The present inventors hope to improve these shortcomings (through intensive research @
Red, the seeds of surfactants used in the production of vinyl polymer emulsions and! By identifying the function, we discovered that it is effective in preventing the sedimentation of starch-based compounds. That is,
It has been revealed that when the zeta potential of the vinyl thread polymer emulsion containing the specified surfactant is within the range of 4 to 40 (-mv), the precipitation of starch compounds is extremely small. 11 The paper adhesive of the present invention is Zeta'1
Vinyl polymer emulsion with position 4 to 40 (-mv) 70 to 90 double leaves and starch compound 10 to 303 &
f, l-%. The present invention will be explained in detail below.

Vinyl polymer emulsions are obtained by emulsion polymerization of vinyl monomers in the presence of a surfactant as an emulsifier, a water-soluble polymer compound as a protective colloid, and a catalyst, and usually have a particle size of 0.1.
~1.5 microns, preferably 0.3-1.1 microns. The above-mentioned surfactants are anionic surfactants, such as higher alcohol salts, alkylbenzenesulfone 4 salts, amphoteric surfactants, such as polyoctyl polyaminoethylglycine, dodecyl polyaminoethylglycine, and nonionic surfactants. Activators such as polyoxyethylene alkyl esters, polyoxyethylene alkyl ethers, polyoxyx-y-L/
7-alkyl phenyl ether, etc. are used.

Among these, nonionic surfactants are preferred, and polyoxyethylene has a molecular weight of 40 to 100 I.
! It is preferably 40 to 80 moles.

1111 is used in an amount of about 15-20% by weight based on the vinyl monomer.

For the water-bath Sumisho molecular compound, polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, etc. are used in amounts of about 2 to 5 layers per vinyl monomer. The catalyst is usually a persulfate, such as potassium persulfate or ammonium persulfate, which is about 0.2 times heavier than the vinyl monomer! It is used as a snack.

Examples of vinyl monomers include Uni 11 vinyl, propionate vinyl, ethylene, vinyl casing, acrylic FR ester, vinyl pyrrolidone, styrene, etc.
Mixed monomers of more than one species can be used. Among these, a combination of vinyl acetate, ethylene, and vinylpyrrolidone is preferred. Further, as the starch-based compound, for example, raw starch, processed starch, various modified starches, etc. can be used. Among them, raw starch is preferably used.

The zeta-IL position is measured using a vinyl system] 1 (the combined emulsion is diluted with distilled water, and the electrophoretic mobility is determined by using a zeta-meter to measure the time during which the particles move by applying a voltage. (μ/sec/V/clrL),
Furthermore, obtain the zeta potential.

Explain zeta potential.

A solid particle suspended in a solution is surrounded by a layer of static positive charge. Also,
This positively charged layer is further in contact with a diffusion layer of opposing ions, and when the particles move through the solution, the positive charge 'tl; A potential difference is created between the two. This potential difference is called zeta potential. The zeta box 1 of a colloidal particle in a solution is proportional to the particle's 11 ω degree.

The zetameter electrophoretic mobility, that is, the moving speed of colloidal particles in a direct current electric field, is measured using a microscope and is calculated based on the Helmholtz-Smolkowski equation.
l' put out. (Zetameter Co., Ltd.) The adhesive for paper of the present invention is a vinyl polymer emulsion (hereinafter abbreviated as the vinyl polymer emulsion g/) having a zeta potential of 4 to 40 (-m) 70 ~90 sub-digestion and 3f powder-based compound 1O to 130-140%, and if the zeta potential of the vinyl polymer emulsion is less than 40% or exceeds 40, the starch-based compound will settle. becomes noticeable, which is not desirable. In addition, when the vinyl polymer emulsion exceeds 70 weight (hours) and 90 weights (in weight), the sedimentation of the powder-based compounds becomes significant, and the adhesion to paper deteriorates.
It is not desirable because it is inferior in quality.

and starch 71 compounds are less than 10% by weight and 30% by weight
If it exceeds the above range, the adhesion performance will be poor and sedimentation will become significant, which is not preferable.

On the other hand, paper such as paperboard, tissue paper, glassine paper, and kraft paper is usually used for '3 near A, but it is not the kind of paper that can be used for 1 to 5 V.

The vinyl-based 41 combined emulsion can be applied to paper using a roll coater, spray, or flow coater.1. It will be actually #jijied at r, but if you use this internal high-speed roll coater, it will be ^-) 3ooy? Preferably 1/min is delivered.

Examples of the present invention and comparative figures are shown below. Furthermore, 1y
l(Xφ indicates the weight 1i standard.

Example 1 45 people of water, 2 parts of polyvinyl alcohol, and 5 parts of polyoxyethylene alkyl fluoride were charged into a polymerization can and heated. 'A ammonium sulfate 0.1
3 parts of releasable vinyl 45 j□di at about 75°C.
After being aged for 1 hour and 30 minutes at approximately 80°C, it was washed in an alkali solution with a solid content of 50% and a zeta potential of 4.3 (
-tl vessel V) vinyl type 7) ij: A combined emulsion was obtained. By blending 25 parts of raw starch with this Emulsicon 75;lk, a paper transfer agent of the present invention was obtained.
Shown in the table.

Example 45 parts of water, 21 parts of polyvinyl alcohol (
, polyoxyethylene alkylphenyl ether 71l
is and heat bath IW v;,, ammonium persulfate 011 41j force +1, l! Emulsion polymerization of 45 vinyl liate was carried out with the same polymerization properties as Hitiya 91J1, solid content 50φ, zeta-lIυ: 15.6 (-nt■
) on vinyl thread was obtained.

10 pieces of raw starch were blended with 90 pieces of this emulsion to obtain a paper adhesive removal agent of the present invention. This precipitated woman's severe nature, ] 茄7f
j 1a-Noh Review 1111I Keishu is shown in Table 1.

115 verses>lil.

Example 1 except that 5 parts of dialkylbenzenesulfonic acid was used instead of polyoxyethylene alkyl phenyl ether, 25 parts of ethyl acrylate and 20 parts of methyl methacrylate were used instead of vinyl nitrate. The emulsifier was combined in exactly the same manner as above, and the solid content was 50% and the zeta-1 was 59.2%.
(-mV) of a vinyl polymer emulsion was obtained.

9 parts of raw starch was blended with 91 parts of this emulsion to obtain an adhesive of a comparative example.

Note 1. Sedimentation Stability tl (11 Stability) Each vinyl polymer emulsion was placed in a glass tube (about 3 cm in diameter) with a depth of about 40 GrrL to a depth of 30+ mm, and then kept at room temperature for a period of Ml [r'j: L , upper part (approximately 20 cm deep to 30 C'rlL) and lower 1ist il: + (tA depth approximately 2 to 10 cm:) rt
) Collect the color emulsion with a Kaoru pipette, each solid Kuma 1! J (the dried residue in the collected emulsion after drying at 105℃ for 3IIIJ is shown by the nail thread) was determined, and the solid content concentration ratio of the lower layer to the solid content of soil layer 1 to 18 of 8% showed stability. .

(2) Dilution stability Each vinyl-based combined emulsion was diluted with e'(i
The stability after standing for 2 days was determined by the same method as the stability in (1), and the dilution stability was determined by 50 times the solid content in the lower part relative to the isomorphic content in the upper part.

Note 2: 5 days toI using a high-speed contact roller (approx. 200μ, 11 parts contact + '7)! −, At1=The state of adhesion of the box was observed after 35 hours of 1+HrU.

patent applicant Daicel Kasei Kogyo Saii Co., Ltd. Procedural amendment (saihe 9) Showa t file/2 II 8 1 ( Commissioner of the Japan Patent Office Kaki-dono (Patent Office Examiner) 1. Indication of the case Designated products and product classification Class 　　　　 3. Person who makes corrections

Claims (1)

[Claims] 70-90% by weight of vinyl polymer emulsion having a zeta potential of 4-40 (-mV) and a starch-based compound IO
Paper adhesive consisting of ~3ON, quantity.