JP5809120B2 - Abrasive paper capable of inkjet recording - Google Patents

Description

  The present invention relates to an abrasive paper capable of ink jet recording.

  The abrasive paper generally has a paper-based support and an abrasive layer containing an abrasive and an adhesive. In a general method for producing abrasive paper, an adhesive is first applied to the surface of the base paper, and a static voltage is applied between the base paper and the abrasive to cause the abrasive to be embedded in the adhesive layer. Thereafter, the adhesive is cured, and the adhesive is further applied and cured from above. There are many processes, but if this process can be replaced with a general base paper making process, considerable labor saving can be achieved. As a result, the production cost can be reduced and the working time can be shortened.

  As an example of the abrasive paper, for example, nail polish sheets described in Patent Documents 1 to 4 can be mentioned. In these sheets, in addition to abrasives such as inorganic particles having a fixed particle size, a functional agent is contained in order to provide functions such as polishing. These sheets have poor disaggregation and little value as a recyclable recovery material, and further have a polishing function, but do not have a paper function, for example, ink jet printing performance.

Japanese Patent No. 3749930 Patent No. 3768204 Japanese Patent No. 3785158 Japanese Patent No. 3910927

  An object of this invention is to provide the abrasive paper which has inkjet printing performance in addition to the polishing ability which can perform precision grinding | polishing. It is another object of the present invention to provide an abrasive paper that can be produced by simplifying a plurality of processes, which is the conventional production of abrasive paper.

  The abrasive paper capable of inkjet recording of the present invention has an abrasive layer provided by applying a coating liquid containing inorganic particles and an adhesive on at least one surface of a support mainly composed of wood fibers. The average particle diameter of the inorganic particles is 10 μm or more, the inorganic particles contain synthetic amorphous silica, and the smoothness of the polishing layer surface is 10 seconds or less. By setting it as such a structure, the sheet | seat which has the characteristic of precision grinding | polishing and inkjet recording ability can be obtained.

  In the present invention, the content ratio of the inorganic particles to the adhesive in the polishing layer may be inorganic particles: adhesive = 100: 50 to 100: 75 in terms of solid content weight ratio. With such a configuration, it is possible to improve the strength of the polishing layer while maintaining the characteristics of precision polishing and ink jet recording suitability.

  In the present invention, the adhesive may be a polyvinyl alcohol resin and / or a vinyl acetate resin. By adopting such a configuration, ink jet recording suitability can be further improved.

In this invention, 7-15 g / m < ² > may be sufficient as the coating amount of the said grinding | polishing layer by an absolutely dry solid weight. By adopting such a configuration, it is possible to further improve the characteristics of precision polishing and ink jet recording suitability.

  In the present invention, the polishing layer may be a polishing layer that has not been flattened. With such a configuration, the characteristics of precision polishing can be further improved.

  In the present invention, the inorganic particles may include an aggregate of synthetic amorphous silica and a positively charged compound. With such a configuration, the characteristics of precision polishing can be further improved. Furthermore, in the present invention, the coating liquid may be a coating liquid containing air by stirring. By adopting such a configuration, it is possible to further improve the precision polishing characteristics and ink jet recording suitability.

  The abrasive paper capable of ink jet recording according to the present invention has precision abrasiveness that is not found in conventional abrasive sheets, and the strength of the surface of the abrasive layer is at a level that does not cause any practical problems, so that it can sufficiently withstand repeated use. Furthermore, the polishing paper of the present invention can withstand the use of ink jet printing because the surface of the polishing layer is excellent in ink jet ink absorbability. By performing inkjet recording on the polishing layer of the polishing paper, it is possible to provide a polishing sheet having excellent design properties. Furthermore, if it is this invention, a general papermaking process can be used and an abrasive paper can be manufactured more simply. In addition, the abrasive paper of the present invention also has value as a recycled material that can be recycled.

  Wood fibers used for the support of the present invention include chemical pulp such as hardwood bleached kraft pulp (LBKP) and softwood bleached kraft pulp (NBKP), wood pulp such as ground pulp, waste paper pulp such as deinked waste paper pulp, etc. Including. In the case of fresh bleached pulp, ECF pulp or TCF pulp is desirable in consideration of the environment. In addition, if necessary, they are mixed by using one or more kinds of conventionally known fillers, binders, sizing agents, fixing agents, yield improvers, paper strength enhancers, etc. It can be obtained after forming a web with various paper machines such as a twin wire paper machine and then drying it. Pulp freeness (CSF) is preferably adjusted to 250 to 600 cc. In the present invention, for example, hardwood bleached sulfate pulp (L-BKP) may be contained in 70% by mass or more, for example, 75 to 100% by mass in the total pulp. In particular, it is desirable to use a support having excellent ink jet ink absorbability.

  A surface paper strength enhancer or a surface sizing agent may be applied to the surface of the support using an apparatus such as a size press, a gate roll, or a sizer for the purpose of imparting sizing properties or surface strength. As the surface sizing agent, general sizing agents such as acrylic, rosin, ASA, AKD can be used. As the surface paper strength enhancer, a general surface paper strength enhancer such as starch, polyacrylamide, polyvinyl alcohol, or carboxymethylcellulose can be used.

  In order to provide polishing performance and ink jet recording performance, a coating layer containing inorganic particles and an adhesive is applied on the base paper to provide a polishing layer. The inorganic particles used there are silica, alumina, and the like. , Magnesia, titania, zirconia, hydroxyapatite and the like. However, in order to impart ink jet printability, it is essential to use synthetic amorphous silica having a porous structure.

  As the inorganic particles, inorganic particles having an average particle diameter of 10 μm or more are used in order to impart polishing performance to the polishing layer. When inorganic particles having an average particle size smaller than this are used, polishing takes time, and satisfactory polishing performance cannot be obtained. In view of ink jet recording suitability, it is desirable to use inorganic particles having an average particle size of 20 μm or less. When the average particle diameter of the inorganic particles contained in the polishing layer exceeds 20 μm, the ink absorbability becomes inferior, and the smoothness of the coating layer surface is remarkably lowered, and there is a possibility that the print quality by ink jet recording cannot be satisfied. is there. Therefore, when sharing precision polishing performance and inkjet printing performance is considered, the average particle diameter of the inorganic particles contained in the polishing layer is preferably 10 to 20 μm, and more preferably 10 to 16 μm. Furthermore, regarding ink jet printing suitability impartment, it is preferable that the inorganic particles be a porous body in view of ink absorbability.

  In the present invention, an adhesive is used for the coating liquid used as the polishing layer. Examples of the adhesive used here include polyvinyl alcohol resins, vinyl acetate resins, cellulose derivatives such as hydroxyethyl cellulose and carboxymethyl cellulose, various latexes such as SBR latex, NBR latex, acrylic latex and chloroprene latex, and urethane resins. be able to. Among these adhesives, it is desirable to use polyvinyl alcohol resins and vinyl acetate resins that are excellent in ink absorbability in order to impart ink jet printability. As the polyvinyl alcohol-based resin, various modified polyvinyl alcohols such as partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, and silanol modification can be used. Polyvinyl acetate and polyethylene vinyl acetate can be used as the vinyl acetate resin.

  In the present invention, the smoothness of the polishing layer is 10 seconds or less. Preferably it is 7 seconds or less, More preferably, it is 5 seconds or less. When the smoothness of the polishing layer exceeds 10 seconds, the surface of the polishing layer has less irregularities and the polishing performance is poor. In consideration of ink jet recording suitability, the smoothness of the polishing layer is preferably 2 seconds or more. Here, the smoothness means a value measured according to JIS P 8119: 1998 “Paper and paperboard—Smoothness test method using Beck smoothness tester”.

  In the present invention, the content ratio of the inorganic particles and the adhesive in the polishing layer is not particularly limited, but, for example, the solid content weight ratio is inorganic particles: adhesive = 100: 30 to 100: 90. be able to. Furthermore, it is preferable to set it as inorganic particle: adhesive agent = 100: 50-100: 75 by solid content weight ratio. A polishing paper having excellent polishing layer strength while maintaining polishing performance and ink jet recording suitability can be obtained. When the ratio of the adhesive is larger than 100: 75, the polishing layer cannot sufficiently absorb the ink-jet ink, which may impair the ink-jet recording suitability. On the other hand, if the ratio of the adhesive is smaller than 100: 50, the inorganic particles are likely to fall off from the polishing layer, which may impair the polishing performance.

  In this invention, about the inorganic particle contained in the coating liquid used as a grinding | polishing layer, you may aggregate the inorganic pigment in the water system. Here, as an example of a method for aggregating the inorganic pigment, there is a method in which a water-soluble polymer having a cationic property as an aggregate is added to an aqueous suspension of the inorganic pigment. In the present invention, synthetic amorphous silica is used as the inorganic particles. For example, since the surface of the synthetic amorphous silica particles is negatively charged, a cationic positive charge is caused. Thus, agglomeration of silica particles occurs. Since the aggregate of the particles has a relatively large lump, when the coating layer is applied, large irregularities are formed, so that polishing performance is imparted. Here, the aggregate for aggregating the inorganic pigment is not particularly limited, but a positively charged compound is preferable. For example, when a synthetic amorphous silica is aggregated, aluminum sulfate is preferable. is there.

  In the present invention, the coating liquid used as the polishing layer is preferably stirred to enclose air. By enclosing air in the coating liquid, it becomes possible to form irregularities on the surface of the polishing layer. The polishing performance can be improved by increasing the degree of unevenness on the surface of the polishing layer. This is because the presence of air bubbles makes the surface of the polishing layer non-smooth and the presence of air causes the coalescence of inorganic pigments (substances come close to each other around the bubbles, resulting in false aggregates. It is presumed that

  The coating liquid used for the polishing layer of the present invention includes, as necessary, a coloring dye, a coloring dye, a dispersant, an antifoaming agent, a viscosity modifier, a crosslinking agent, a release agent, an antiseptic, a softener, and a wax. Further, a conductive agent, an antistatic agent, a fragrance, a deodorant, a flameproofing agent, a repellent, a rustproofing agent and the like can be used as appropriate. Here, a cationic water-soluble polymer that is positively charged, various metal ions, or the like can be applied as the agent that causes aggregation of the inorganic pigment.

  As for the coating liquid for providing the polishing layer, a known general coating machine such as a blade coater, a roll coater, an air knife coater, a rod coater or the like can be used.

The dry coating amount of the polishing layer is preferably 7 to 15 g / m ² . If it is less than 7 g / m ² , it is difficult for the polishing layer to completely cover the support surface. Therefore, the polishing performance may vary depending on the location. In addition, ink absorbability cannot be ensured and ink jet printing suitability may be poor. On the other hand, if the dry coating amount exceeds 15 g / m ² , the adhesive strength between the polishing layer and the support may not be practically usable. In the subsequent process, for example, cutting of the abrasive paper may cause inefficiency in the process work due to the removal of the polishing layer.

  The polishing layer of the present invention may be applied with a coating solution on a base paper and then subjected to a flattening process such as a calendar process. However, if the unevenness on the surface of the polishing layer is completely crushed, the polishing performance is impaired. Therefore, it is necessary to treat the surface of the polishing layer to the extent that the irregularities remain. Preferably, the planarization process is not performed.

  Hereinafter, the present invention will be described more specifically by way of examples and comparative examples, but the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in an Example show a mass part and mass%, respectively.

<Example 1>
<Creation of base paper>
A pulp slurry of 100 parts of LBKP (Canadian Standard Freeness: CSF = 500 ml) was made with a long net paper machine to obtain a base paper having a basis weight of 180 g / m ² .
<Preparation of coating liquid for polishing layer>
Synthetic amorphous silica having an average particle size of 16 μm (trade name: Silojet P616, manufactured by Grace Devison Co., Ltd.) in an aqueous suspension in which 10 parts of aluminum sulfate and polyvinyl alcohol (trade name: PVA-117) are dispersed. (Manufactured by Kuraray Co., Ltd.) were sequentially added and sufficiently stirred to obtain a coating solution having a solid concentration of 15%. This agitation was performed at a relatively slow rotational speed so that no air was involved. Here, when aluminum sulfate was added, the viscosity of the suspension (aggregation of synthetic amorphous silica) was visually confirmed during stirring, and then polyvinyl alcohol was added.
<Formation of polishing layer>
Apply the coating solution obtained above on one side of the base paper with an air knife coater so that the dry coating amount is 10 g / m ^2, and dry with hot air with an air dryer to obtain the desired abrasive paper It was.

<Example 2>
In Example 1, the target abrasive paper was obtained in the same manner as in Example 1 except that the number of parts of polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) was changed to 70 parts.

<Example 3>
In Example 1, the target abrasive paper was obtained in the same manner as in Example 1 except that the coating amount of the coating liquid used as the polishing layer was changed to 7 g / m ² .

<Example 4>
In Example 1, the target abrasive paper was obtained in the same manner as in Example 1, except that the coating amount of the coating liquid used as the polishing layer was changed to 15 g / m ² .

<Example 5>
In Example 1, synthetic amorphous silica (trade name: Silojet P616, manufactured by Grace Devison) with an average particle diameter of 16 μm was synthesized with synthetic amorphous silica (trade name: Silojet P612, Grace Devison, with an average particle diameter of 12 μm). The target abrasive paper was obtained in the same manner as in Example 1 except that the product was changed to “manufactured”.

<Example 6>
In Example 1, when preparing the coating liquid used as the polishing layer, aluminum sulfate was not added, the resulting coating liquid was vigorously stirred, and air was entrained, thereby allowing countless numbers in the liquid. A target abrasive paper was obtained in the same manner as in Example 1 except that the bubbles were encapsulated. It was confirmed that the coating liquid prepared here had innumerable bubbles in the liquid under standing conditions.

<Example 7>
In Example 1, the target abrasive paper was obtained in the same manner as in Example 1 except that aluminum sulfate was not added when adjusting the coating liquid to be the polishing layer.

<Example 8>
In Example 1, the target abrasive paper was obtained in the same manner as in Example 1 except that the number of parts of polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) was changed to 40 parts.

<Example 9>
In Example 1, the target abrasive paper was obtained in the same manner as in Example 1 except that the number of parts of polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) was changed to 80 parts.

<Example 10>
The same purpose as in Example 1 except that 50 parts of polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) was changed to 50 parts of synthetic latex (trade name: E1794, manufactured by Asahi Kasei Chemical Co., Ltd.). A polishing paper was obtained.

<Example 11>
Example 1 is the same as Example 1 except that 50 parts of polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) is changed to 50 parts of urethane resin (trade name: Passcoal JK-831N, manufactured by Meisei Chemical Co., Ltd.). Thus, the intended abrasive paper was obtained.

<Example 12>
In Example 1, the target abrasive paper was obtained in the same manner as in Example 1 except that the coating amount of the coating liquid used as the polishing layer was changed to 5 g / m ² .

<Example 13>
In Example 1, the target abrasive paper was obtained in the same manner as in Example 1 except that the coating amount of the coating liquid used as the polishing layer was changed to 16 g / m ² .

<Example 14>
In Example 1, synthetic amorphous silica having an average particle size of 16 μm (trade name: Silojet P616, manufactured by Grace Devison) was synthesized with synthetic amorphous silica having an average particle size of 10 μm (trade names: Sunsphere NP100, AGC ES). A target abrasive paper was obtained in the same manner as in Example 1 except that the product was changed to (made by ITEC).

<Example 15>
In Example 1, synthetic amorphous silica (trade name: Silojet P616, manufactured by Grace Devison Co., Ltd.) having an average particle diameter of 16 μm was synthesized with synthetic amorphous silica (trade name: Sunsphere NP200, AGC ES) having an average particle diameter of 20 μm. A target abrasive paper was obtained in the same manner as in Example 1 except that the product was changed to (made by ITEC).

<Example 16>
In Example 1, polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) was changed to polyethylene vinyl acetate resin (trade name: Polysol EVA AD 50, manufactured by Showa Polymer Co., Ltd.). The desired abrasive paper was obtained.

<Comparative Example 1>
In Example 1, synthetic amorphous silica having an average particle diameter of 16 μm (trade name: Silojet P616, manufactured by Grace Devison) was synthesized with synthetic amorphous silica having an average particle diameter of 9 μm (trade name: P409, manufactured by Grace Devison). The target abrasive paper was obtained in the same manner as in Example 1 except that the above was changed.

<Comparative Example 2>
In Example 1, a synthetic amorphous silica having an average particle size of 16 μm (trade name: Silojet P616, manufactured by Grace Devison) was used as a synthetic amorphous silica having an average particle size of 5 μm (trade name: ED5, manufactured by Grace Devison). The target abrasive paper was obtained in the same manner as in Example 1 except that the above was changed.

<Comparative Example 3>
In Example 1, synthetic amorphous silica having an average particle diameter of 16 μm (trade name: Silojet P616, manufactured by Grace Devison) was changed to alumina (trade name: A31, manufactured by Nippon Light Metal Co., Ltd.) having an average particle diameter of 5 μm. Except that, the target abrasive paper was obtained in the same manner as in Example 1.

<Comparative Example 4>
In Example 1, synthetic amorphous silica having an average particle size of 16 μm (trade name: Silojet P616, manufactured by Grace Devison) was changed to clay (Kaming Ross, manufactured by Keimin) having an average particle size of 2 μm or less. Was the same as in Example 1 to obtain the intended abrasive paper.

<Comparative Example 5>
In Example 1, synthetic amorphous silica (trade name: Silojet P616, manufactured by Grace Devison Co., Ltd.) having an average particle diameter of 16 μm has a major axis of 1.5 to 2.5 μm and a minor axis of 0.1 to 0.3 μm. A target abrasive paper was obtained in the same manner as in Example 1 except that calcium carbonate (Tama Pearl TP123CS, manufactured by Okutama Kogyo Co., Ltd.) was used.

  Table 1 shows the evaluation results of the abrasive paper obtained in each Example and Comparative Example. Each evaluation was performed by the method shown below.

<Smoothness>
It was measured according to “Paper and paperboard—Smoothness test method using Beck smoothness tester” defined in JIS P 8119: 1998.
<Polishability>
The nail was rubbed with the abrasive layer of the abrasive paper, and the state after rubbing was visually observed and evaluated in the following three stages.
Evaluation criteria:
○ − Polished, no roughness of the polished surface and no practical problem.
Δ − Slightly difficult to polish and rough surface remains, but no problem in practical use.
× − Almost no polishing and practical problems.

<Inkjet printing suitability>
EP-801A manufactured by EPSON was selected as the ink jet printer, and solid and fine lines were printed on the surface of the polishing layer of the polishing paper. The ink jet printing suitability (IJ suitability) was evaluated in the following three stages, with respect to the bleeding and color developability of the printed portion, with the following three steps.
○ − Little ink bleeding, good color development, no practical problems.
Δ-Ink bleeding and color development are slightly inferior, but there are no practical problems.
× − Ink bleeding and poor color developability have practical problems.

<Water resistance of inkjet printing>
EP-801A manufactured by EPSON was selected as the ink jet printer, and solid and fine lines were printed on the surface of the polishing layer of the polishing paper. Water droplets were dropped on the printing part, and after drying at room temperature, the ink bleeding (IJ water resistance) was evaluated by the following three steps in relation to the ink bleeding.
○ − There is little ink bleeding and no practical problems.
Δ-Ink ooze out slightly, but there is no practical problem.
× − Ink bleeding is conspicuous and has practical problems.

  As is clear from the above results, the abrasive paper obtained in each example had good polishing suitability, ink jet printing suitability and printing water resistance.

Claims (14)

On at least one surface of a support mainly composed of wood fibers, has it containing the inorganic particles and adhesive Ken Migakuso,
The average particle diameter of the inorganic particles is 10 to 20 μm,
The inorganic particles comprise synthetic amorphous silica;
The smoothness of the polishing layer surface is 10 seconds or less,
A polishing paper capable of ink jet recording, wherein the inorganic particles are aggregates of a synthetic amorphous silica and a positively charged compound. 2. The ink jet recording according to claim 1, wherein the content ratio of the inorganic particles and the adhesive in the polishing layer is a solid weight ratio of inorganic particles: adhesive = 100: 50 to 100: 75. Polishing paper. The abrasive paper capable of ink jet recording according to claim 1 or 2, wherein the adhesive is a polyvinyl alcohol resin and / or a vinyl acetate resin. The abrasive paper capable of ink jet recording according to any one of claims 1 to 3 , wherein the coating amount of the abrasive layer is 7 to 15 g / m ² in terms of absolute dry weight. The abrasive paper according to any one of claims 1 to 4 , wherein the abrasive layer is an abrasive layer that has not been flattened. Wherein the inorganic particles are aggregates of charged compound synthetic amorphous silica and positively charged, claim 1-5 in which charged compounds positive charge and wherein the aluminum sulfate A polishing paper capable of inkjet recording as described in 1. The abrasive paper according to any one of claims 1 to 6 , wherein the inorganic particles contain synthetic amorphous silica having an average particle diameter of 10 to 16 µm.   A polishing layer is provided by applying a coating solution containing inorganic particles and an adhesive on at least one surface of a support mainly composed of wood fibers,
  The average particle diameter of the inorganic particles is 10 to 20 μm,
  The inorganic particles comprise synthetic amorphous silica;
  The smoothness of the polishing layer surface is 10 seconds or less,
A method for producing abrasive paper capable of ink jet recording, wherein the inorganic particles are aggregates of synthetic amorphous silica and a positively charged compound. A polishing layer is provided by applying a coating solution containing inorganic particles and an adhesive on at least one surface of a support mainly composed of wood fibers ,
The average particle diameter of the inorganic particles is 10 to 20 μm,
The inorganic particles comprise synthetic amorphous silica;
The smoothness of the polishing layer surface is 10 seconds or less,
A method for producing abrasive paper capable of ink jet recording, wherein the coating liquid is a coating liquid containing air by stirring . The ink jet recording according to claim 8 or 9, wherein the content ratio of the inorganic particles and the adhesive in the polishing layer is a solid weight ratio of inorganic particles: adhesive = 100: 50 to 100: 75. A method for manufacturing abrasive paper. The method for producing abrasive paper capable of ink jet recording according to any one of claims 8 to 10, wherein the adhesive is a polyvinyl alcohol resin and / or a vinyl acetate resin. The coating amount of the polishing layer is 7 to 15 g / m in absolute dry solid weight. ² The method for producing abrasive paper capable of ink jet recording according to any one of claims 8 to 11, wherein: The method for producing abrasive paper capable of inkjet recording according to any one of claims 8 to 12, wherein the abrasive layer is an abrasive layer that has not been flattened. The inorganic particles are aggregates of synthetic amorphous silica and a positively charged compound, and the positively charged compound is aluminum sulfate. A method for producing an abrasive paper capable of inkjet recording as described in 1.