KR101154463B1 - Latex for coating paper with the enhanced property of film forming - Google Patents

Abstract

The present invention relates to a latex for paper coating, and more particularly to a latex for paper coating comprising 0.001 to 5 parts by weight of a metal oxide compound based on 100 parts by weight of styrene-butadiene-based latex, It relates to a paper coating latex and the paper coating liquid composition containing an inorganic pigment in the paper coating latex having an effect of improving the film formation to improve the adhesion.

Moreover, this invention relates to the paper manufactured by apply | coating said paper coating liquid composition.

Metal oxide, film formation, adhesion, paper coating solution, latex, paper

Description

Latex for coating paper with the enhanced property of film forming}

The present invention relates to a latex for paper coating, and more particularly, to a latex for paper coating having an effect of improving the crosslinking reaction of the latex to improve printability and a paper coating liquid composition comprising the latex.

In general, the paper coating liquid is composed of inorganic pigments, latex, and other additives. Among them, the latex for paper coating serves as a binder between the inorganic pigment and the paper. After the paper coating liquid is applied onto the paper and subjected to a drying process, the latex forms a film and exerts an adhesive force between the paper and the inorganic pigment.

Thus, the adhesion of the paper coating layer is determined by how the latex dries and what type of film it forms. When the latex film is made of a dense form, the adhesion, the wet adhesion, and the like are improved.

The surface of the latex is in the form of carboxylic acid to ensure the stability of the latex, and this carboxylic acid forms an electric double layer on the latex surface and contributes to stabilization of the latex since it has an electrostatic repulsive force.

As the latex is dried, the distance of latex particles becomes closer as the water of latex evaporates. When the latex particles meet, the polymer chains on the surface of the latex particles are entangled and connected to form a continuous film. . At this time, the carboxylic acid on the latex surface serves to interfere with the latex particles approach each other. Therefore, there is a problem that the formation of the latex film is slow.

In order to solve the problems of the prior art as described above, an object of the present invention is to provide a latex for paper coating to improve the adhesion by promoting the film formation of the latex without changing the structure and shape of the latex.

It is another object of the present invention to provide a paper coating liquid composition comprising the latex for paper coating.

In addition, an object of the present invention is to provide a paper prepared by applying the above-described paper coating latex and paper coating liquid composition.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention provides a latex for paper coating, comprising 0.001 to 5 parts by weight of a metal oxide compound based on 100 parts by weight of styrene-butadiene-based latex.

The metal oxide compound is an inorganic oxide, and is at least one member selected from the group consisting of zinc oxide, magnesium oxide, titanium oxide, silicon oxide, calcium oxide, and tin oxide.

In particular, the metal oxide compound is preferably zinc oxide or magnesium oxide.

In another aspect, the present invention provides a paper coating liquid composition comprising the latex and inorganic pigment for paper coating.

The inorganic pigment is preferably included in 50 to 99 parts by weight based on 100 parts by weight of the paper coating liquid composition.

The inorganic pigment may be selected from inorganic compounds including calcium carbonate, clay, silicon, aluminum, zinc, zirconium, titania.

In particular, the inorganic pigment is preferably a mixture of calcium carbonate and clay.

The paper coating liquid composition may further include at least one additive selected from the group consisting of thickeners, lubricants, water resistant agents and fluorescent agents.

In another aspect, the present invention provides a paper prepared by applying the above-mentioned paper coating latex and paper coating liquid composition.

Paper coating latex for paper coating, the paper coating latex for paper coating and inorganic pigments, characterized in that the film formation of the present invention contains a metal oxide compound can be expected to improve the film formation, the paper coating liquid composition It is effective to provide a coating paper having excellent printability by applying.

Although described in detail above with reference to the specific embodiments of the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and such variations and modifications are defined in the appended claims. It is natural to belong.

Hereinafter, the present invention will be described in detail.

In the present invention, the metal oxide compound is included in the latex as a form in which the reaction is terminated by addition to the latex paper coating. The paper produced by coating the coating composition containing the latex thus prepared on paper is improved adhesion.

If the metal oxide compound is added during the drying process after the paper coating liquid is applied onto the paper, it may promote the film formation of the latex. It is thought that this is because metal oxide chelates the carboxylic acid on the latex particle surface to facilitate access between the latex particles, and also acts as a crosslinking agent between the latex particles and the particles to improve film formation.

a) Manufacture of latex for paper coating with improved film formation

The paper coating latex having improved film formation of the present invention is a paper coating latex prepared by adding a metal oxide compound to the paper coating latex in which the reaction is terminated.

The paper coating latex may be a styrene-butadiene-based latex prepared by a known emulsion polymerization method.

The styrene-butadiene-based latex conversion is 96 to 99%, the solid content is preferably 40 to 55%.

As the metal oxide compound, zinc oxide, magnesium oxide, titanium oxide, silicon oxide, calcium oxide, tin oxide, or the like may be used as the inorganic oxide.

The metal oxide compound is preferably used in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the latex. If the content is less than 0.001 parts by weight, there is a problem that there is no film forming improvement effect, if the content exceeds 5 parts by weight there is a problem that the paper properties are lowered.

When the metal oxide compound is dispersed in the latex for paper coating, the input temperature is preferably 20 to 40 ° C., and a latex for paper coating which promotes film formation by stirring for 10 minutes may be prepared.

b) paper coating liquid composition preparation

Paper coating liquid composition of the present invention is a paper coating liquid composition comprising a latex and inorganic pigment for paper coating prepared in the step (a).

The latex for paper coating prepared in (a) can be used as a binder.

The inorganic pigment may be used alone or in combination of two or more kinds of inorganic compounds such as calcium carbonate, clay, silicon, aluminum, zinc, zirconium, titania, or a commercially available product in the form of a slurry.

The inorganic pigment is preferably used in 50 to 99 parts by weight based on 100 parts by weight of the paper coating liquid composition.

In addition, the paper coating liquid composition may further comprise various additives such as thickeners, lubricants, water-resistant agents, fluorescent agents and the like.

c) coated paper

The paper of this invention is coated paper manufactured by apply | coating the paper coating liquid composition of said (b) to a base paper.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example 1

(a) Preparation of latex for paper coating

A conversion rate of 98% and a solid content of 50% were added to 0.05 parts by weight of zinc oxide to 100 parts by weight of a latex for styrene-butadiene paper coating and prepared by dispersing for 10 minutes using a stirrer.

(b) preparing a paper coating liquid composition

13 parts by weight of the paper coating latex prepared in (a), 60 parts by weight of primary clay, 40 parts by weight of calcium carbonate and 1.3 parts by weight of starch were added, and distilled water was added so that the solid content of the coating solution composition was 67.3%. .

(c) coating paper manufacturing

The coating solution composition of (b) is coated on a base paper and coated under the following conditions.

It was prepared by.

Coating: Rod Coating, No 6

Drying: Oven, 105 ℃, 30 seconds

Calendar: Supercalendar, 80 ℃, 100kg / cm, 4m / min, 2 passes

Original paper: Commercial raw paper (Basic weight 72gsm)

Example  2

Except for adding 0.1 parts by weight of zinc oxide in Example 1 was carried out in the same manner as in Example 1.

Example  3

Except for adding 0.5 parts by weight of zinc oxide in Example 1 was carried out in the same manner as in Example 1.

Example  4

Except for adding 1 part by weight of zinc oxide in Example 1 was carried out in the same manner as in Example 1.

Example  5

Except for adding 0.1 parts by weight of magnesium oxide in Example 1 was carried out in the same manner as in Example 1.

Example  6

Except for adding 0.5 parts by weight of magnesium oxide in Example 1 was carried out in the same manner as in Example 1.

Example  7

Except for adding 1 part by weight of magnesium oxide in Example 1 was carried out in the same manner as in Example 1.

Comparative example  One

The same process as in Example 1 was carried out except that zinc oxide was not used in Example 1.

Comparative example  2

Except for adding 0.0005 parts by weight of zinc oxide in Example 1 was carried out in the same manner as in Example 1 .

Comparative example  3

Except for adding 10 parts by weight of zinc oxide in Example 1 was carried out in the same manner as in Example 1.

The physical properties of the paper coating latex, paper coating liquid composition and coated paper prepared according to the Examples and Comparative Examples were measured by the following method and the results are shown in the following table.

Low shear viscosity: A BF type viscometer is used. The coating liquid viscosity is expressed as a value (unit: cPs) measured after 1 minute at 60 rpm using a No. 3 rotor.

* High shear viscosity: measured using a Hercules Viscometer (KRK type, model KC-801C) at 6600 rpm (unit: cPs).

* Adhesive force: After printing several times in RI printing machine, the degree of tearing was visually judged and evaluated by the 5-point method. The higher the score, the better the adhesion. After the measurement using the inks of Tack Values 12, 14 and 16, respectively, the average value was obtained.

* Water Resistance (Wet Adhesion): Printed after adding wet water using a Morton roll in an RI printing machine, and measuring the degree of tearing in the same manner as the above-described adhesion. It measured after printing once using the ink of the tag value 14.

      * Ink drying speed: After printing on the RI printer, the degree of ink leakage with time was measured by the five-point method. The higher the score, the faster the ink drying speed.

      * Rotability: Print after adding wet water in RI printing machine to measure the degree of ink transfer. Low tag value ink was used to prevent tearing. The higher the score, the higher the developability.

      * White paper gloss: Using the Optical Gloss Meter (HUNTER type, 75 ° ~ 75 °), various parts of the coated paper was measured and averaged.

      * Glossy printing: 24 hours after printing on RI printing machine, it is measured by the same method as white gloss.

The physical property evaluation results of the paper coating liquid composition of the present invention are shown in Table 1 below.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 1 Comparative Example 2 Comparative Example 3 Low shear
Viscosity 870 cPs 880 cPs 875 cPs 860 cPs 870 cPs 875 cPs 865 cPs 875 cPs 880 cPs 810 cPs High shear
Viscosity 38.5 cPs 20.4 cPs 20.3 cPs 20.6 cPs 20.4 cPs 20.5 cPs 20.3 cPs 20.3 cPs 20.9 cPs 21.1 cPs Conservative 156.8 157.0 157.2 158.0 156.9 157.5 157.5 156.9 157.0 163.0 Adhesion 4.1 4.3 4.3 4.3 4.2 4.2 4.3 4.0 4.0 3.5 Wetting
Adhesion 4.1 4.3 4.3 4.3 4.2 4.2 4.3 4.0 4.0 3.5 ink
Drying speed 4.0 4.0 4.1 4.1 4.0 4.1 4.1 4.0 4.0 4.3 Cultivation 4.1 4.1 4.0 4.1 4.0 4.1 4.0 4.0 4.1 4.0 White paper 70.0 70.1 70.8 71.0 70.1 70.2 70.2 70.0 70.1 69.5 Printing gloss 89.5 89.4 89.2 89.3 89.0 89.0 88.8 89.5 89.3 87.0

Examples 1 to 7 of the present invention can be confirmed that the adhesion, the wet adhesion is improved compared to Comparative Examples 1 to 3. The film formed from the coating liquid composition of the present invention has a dense form and shows improved results in adhesive strength and the like. In addition, the paper coated from the coating liquid composition of the present invention showed excellent results compared to the comparative example in several properties such as ink drying speed, tackiness, white paper gloss and printing gloss.

Claims (10)

A latex for paper coating, comprising 0.001 to 5 parts by weight of a metal oxide compound based on 100 parts by weight of styrene-butadiene-based latex. The paper coating latex according to claim 1, wherein the metal oxide compound is included in a form dispersed in styrene-butadiene-based latex. The paper coating latex according to claim 1, wherein the metal oxide compound is an inorganic oxide, and is at least one selected from the group consisting of zinc oxide, magnesium oxide, titanium oxide, silicon oxide, calcium oxide, and tin oxide. . The paper coating latex according to claim 2, wherein the metal oxide compound is zinc oxide or magnesium oxide. Paper coating liquid composition characterized in that it comprises a latex and inorganic pigment for paper coating of claim 1. The paper coating liquid composition according to claim 5, wherein the inorganic pigment is contained in an amount of 50 to 99 parts by weight based on 100 parts by weight of the paper coating liquid composition. The paper coating liquid composition according to claim 5, wherein the inorganic pigment is at least one selected from inorganic compounds including calcium carbonate, clay, silicon, aluminum, zinc, zirconium and titania. 6. The paper coating liquid composition according to claim 5, wherein the inorganic pigment is a mixture of calcium carbonate and clay. The method of claim 5, The paper coating liquid composition further comprises at least one additive selected from the group consisting of thickeners, lubricants, water resistant agents and fluorescent agents. The paper characterized in that the surface is coated with the coating liquid composition of any one of claims 5 to 9.