JP4016057B1 - Wallpaper backing paper - Google Patents

Abstract

[PROBLEMS] To provide a backing paper for wallpaper which can be processed by foaming a resin such as a vinyl chloride resin or an olefin resin, has high dimensional stability and concealment property, and is capable of re-peeling the wallpaper when reforming. Provides a good backing paper for wallpaper.
As a raw material, the backing paper for wallpaper, which contains 5 to 65% by mass of mechanical pulp and 5 to 18% by mass of ash, is measured according to the heat flow meter method of JIS-A1412-2. The thermal conductivity is 0.2 to 0.5 W / (m · K). The filler is inorganic particles having a specific heat of 1.2 J / g / deg or less at a temperature of 230 ° C. The filler is preferably a regenerated particle aggregate obtained by dehydrating and drying, firing, and pulverizing using clay and / or deinking floss discharged in the used paper deinking process.
[Selection figure] None

Description

  The present invention relates to a base paper (backing paper) such as vinyl wallpaper or paper wallpaper, and more particularly to a backing paper for wallpaper which is excellent in adhesion processability and workability with synthetic resins such as vinyl chloride resin and olefin resin.

  The wallpaper is made of a wallpaper backing paper and a synthetic resin such as vinyl chloride resin or olefin resin coated, dried and bonded to the wallpaper backing paper. For wallpaper backing paper used for wallpaper, in addition to dimensional stability and concealment, the synthetic resin applied to the wallpaper backing paper will foam well, and the wallpaper backing paper will re-peel well during renovation Etc. are required.

  The wallpaper is bonded to the wall with an aqueous paste such as starch or vinyl acetate. At that time, when the dimensional stability of the wallpaper backing paper is poor, the wallpaper backing paper contracts and an opening occurs at the joint portion of the wallpaper.

  Regarding the dimensional stability of backing paper for wallpaper, for example, as a method for preventing opening during wallpaper construction, JP 2005-82894 A uses a drying method with a Yankee dryer in the paper making process, A method is proposed in which is set to 10 to 2000 seconds. JP-A-2005-154968 discloses that pulp components are mixed with synthetic resin fibers such as vinyl chloride copolymer, vinyl acetate copolymer, acrylic, olefin, and polyester as synthetic resin components. A method of improving curling and underwater elongation due to the influence of glue or the like has been proposed from paper made of paper only.

  However, dimensional stability is certainly improved by controlling the sizing to a specific range or mixing synthetic resin fibers at the paper making stage, but in particular the latter requires expensive synthetic resin fibers to be mixed at the paper making stage. The cost of backing paper for wallpaper is high. In addition, these methods can solve the concealment problem, the foaming problem of the synthetic resin applied to the wallpaper backing paper, and the re-peelability problem during renovation, which are required for wallpaper backing paper. is not.

  In addition, the surface of the wallpaper is covered with a surface layer material such as vinyl chloride resin or olefin resin. However, due to environmental problems such as disposal of the removed wallpaper and resource saving, which occurs when the wallpaper is replaced by remodeling. In recent years, the thickness of the surface material, which is a synthetic resin, has been reduced, and in order to prevent the wall material from being transferred to the wallpaper surface, it is desired to improve the concealability of the backing paper.

  As a method for enhancing the concealing property, there is a method by blending a filler. In Japanese Patent No. 3715739, calcined clay having an average particle size of 3 μm or less or kaolin having an average particle size of 8 μm or less is used. JP-A-2004-353112 proposes a method of blending 5 to 50% by mass of kaolin having an average particle size of 3 μm or less as a filler type in paper.

  However, these are effective as a method for obtaining concealment, but are required for wallpaper backing paper, foaming problems of synthetic resin applied to wallpaper backing paper, problems of removability at the time of reforming Cannot be solved. Moreover, there is a problem that the strength of the backing paper for wallpaper is lowered, and problems such as tearing occur at the time of enforcement.

  Further, as a method for improving the foamability of a vinyl chloride resin at the time of producing a backing paper for wallpaper, Japanese Patent Application Laid-Open No. 8-100309 discloses the particle diameter of aluminum hydroxide and the content of inorganic powder in a specific range. Further, the density of the flame retardant paper before the machine calendar process is set to a specific range, and the thermal conductivity of the backing paper for wallpaper is set to a specific range (0.35 to 0.4 W / (m · K)). Thus, a method for improving foamability has been proposed.

  However, in this method, it is necessary to contain 75 to 85% by mass of aluminum hydroxide in the backing paper for wallpaper, and in general paper machines, troubles such as paper breakage, pitch and wrinkles occur, and operability is greatly deteriorated. . In addition, because it contains a large amount of inorganic particles in the wallpaper backing paper, it has excellent concealment and dimensional stability, but it is difficult to obtain the rigidity, strength and interlayer strength required for wallpaper backing paper. In addition, there is a problem of workability and removability at the time of reforming, and it cannot be used as a general backing paper. That is, as described in Japanese Patent Application Laid-Open No. 8-100309, it relates to a specific backing paper called flame retardant paper.

  Therefore, in addition to dimensional stability and concealability, there is a need to provide a wallpaper backing paper in which the synthetic resin applied to the wallpaper backing paper foams well and the wallpaper backing paper re-removes well during renovation. Is the actual situation.

JP 2005-82894 A JP 2005-154968 A Japanese Patent No. 3715739 JP 2004-353112 A Japanese Patent Laid-Open No. 8-100389

  Therefore, the main problem to be solved by the present invention is that the wallpaper backing paper can be processed by foaming a resin such as vinyl chloride resin or olefin resin, and has high dimensional stability and concealment. Moreover, it is to provide a backing paper for wallpaper having good removability of the wallpaper at the time of reforming.

  In order to solve the above problems, the present invention has the following configuration.

[Invention of Claim 1]
A backing paper for wallpaper mainly composed of pulp and filler as raw materials, wherein the pulp contains 5 to 65% by mass of mechanical pulp, and the ash content of the backing paper for wallpaper measured according to JIS-P 8252 The filler is contained so as to be 5 to 18% by mass, and as the filler, the deinking floss generated in the deinking process of the used paper processing process for producing the used paper pulp is used as a main raw material, dehydrated and dried, and baked. The recycled particle aggregate obtained by pulverizing and agglomerating in the firing step is used, and the thermal conductivity of the backing paper for wallpaper measured according to the heat flow meter method of JIS-A1412-2 is 0.2-0. Backing paper for wallpaper characterized by being 5 W / (m · K).

(Function and effect)
By adding a filler so that the mechanical pulp is 5 to 65% by mass in the total pulp and the ash content is 5 to 18% by mass, the thermal conductivity is 0.2 to 0.5 W / (m · K), and chlorination is performed. Resin foamability at the time of coating such as vinyl resin and olefin resin can be improved, and troubles such as cracking of the resin layer at the time of wallpaper construction due to poor resin foaming can be prevented. Further, the concealability of the wallpaper backing paper is improved, and the wall material can be prevented from being projected onto the wallpaper surface. In addition, the regenerated particle aggregate having a specific component as a filler has a low specific heat in a temperature range of 230 ° C., and can improve the resin foaming property when coating vinyl chloride resin, olefin resin, etc. Moreover, the backing paper for wallpaper which has a high opacity improving effect and high concealability can be obtained.

[Invention of Claim 2]
2. The wallpaper backing paper according to claim 1, wherein the filler is inorganic particles having a specific heat measured in accordance with JIS-K7123 at a temperature of 230 [deg.] C. of 1.2 J / g / deg or less.

(Function and effect)
In particular, by using a filler having a specific heat at a temperature of 230 ° C. of 1.2 J / g / deg or less, the thermal conductivity of the backing paper for wallpaper is set to 0.2 to 0.5 W / (m · K). The resin foaming property at the time of applying a synthetic resin such as an olefin resin can be improved.

  Next, an embodiment of the present invention will be described.

  The wallpaper backing paper of the present invention can be produced with a paper machine comprising a normal long mesh, circular mesh, short mesh, slanted wire part, etc., with a slurry containing pulp and filler as main raw materials and the necessary chemicals. The machine is not particularly limited. Also, the drying process may be any of a normal multi-cylinder dryer, a Yankee dryer, etc.In particular, by using a Yankee dryer, it is possible to obtain a backing paper for wallpaper that is superior in dimensional stability than a drying method using a multi-cylinder dryer. This is preferable. The drying method using a Yankee dryer is different from the drying method using a general multi-cylinder dryer, and wet paper is attached to the cylinder surface for drying. This reduces paper shrinkage during drying and is used as wallpaper backing paper. When the water-based paste is applied to the wall, the paper is less stretched, has excellent dimensional stability, and can be particularly suitable for wallpaper backing paper.

  As the mechanical pulp used in the present invention, GP (Grandwood pulp), PGW (Pressurized Grandwood pulp), TMP (Thermomechanical pulp) and the like can be used. Bleached pulp may be used, and for example, BCTMP or the like that has been subjected to a bleaching treatment can also be suitably used.

  As other pulps, kraft pulp, semi-chemical pulp and the like can be used.

  As raw materials for obtaining pulp, in addition to wood raw materials such as conifers and broad-leaved trees, non-wood raw materials such as hulls, hemp and kenaf can be used.

  Further, recycled pulp derived from waste paper containing or not containing mechanical pulp can also be used.

  The blending ratio of the mechanical pulp is 5 to 65% by mass in the total pulp in order to obtain a desired concealing property. Furthermore, it is preferable to make it contain 20-50 mass% from the point etc. which prevent the generation | occurrence | production of the blister of the coated resin at the time of removability of the backing paper for wallpaper at the time of renovation, and make it contain 30-50 mass% More preferred. When the content of mechanical pulp is less than 5% by mass, the opacity of the backing paper for wallpaper is lowered, causing a problem of reflection of the wall material on the surface of the wallpaper. Moreover, the interlayer strength (internal bond) of the backing paper for wallpaper will become high as the content rate of mechanical pulp is less than 5 mass%. In general paper such as printing paper and paperboard, it is required that the interlayer strength is high. However, in the backing paper for wallpaper in the present invention, if the interlayer strength is high, it is peeled off at the time of reform after being bonded to the wall. The work efficiency is reduced. That is, in the application of the present invention product, it is necessary to adjust the interlayer strength within a certain range so that the wallpaper can be easily peeled off when the wallpaper is peeled off at the time of remodeling. When the backing paper has a high interlayer strength, not only does it require a strong force to peel off the wallpaper during renovation, but part of the backing paper remains on the wallpaper side, part of the backing paper remains on the wall side, and on the wall surface. Since the unevenness is generated, the wallpaper to be pasted cannot be pasted neatly. On the other hand, if the content of mechanical pulp exceeds 65% by mass, the interlaminar strength becomes too low, and unintentional peeling may occur. Moreover, in order to adjust the interlaminar strength, a strength auxiliary agent such as excessive addition of a paper strength enhancer is required, which not only increases the cost, but also increases the cost by the resin component (lignin) in the system. Dirt is likely to occur, resulting in a decrease in operability.

  Moreover, when mechanical pulp is contained exceeding 65 mass%, there exists a possibility that the fall of not only interlayer strength but tensile strength may be caused, and a problem may arise. That is, when a wallpaper is pasted on a colonnade of a building, the wallpaper having a length of 4 to 5 m is used, but the wallpaper may be broken by a slight external force and the weight of the wallpaper.

  The backing paper for wallpaper of the present invention has an interlaminar strength (internal bond) that is excellent in wallpaper releasability at the time of renovation while obtaining desired hiding properties by containing 5 to 65% by mass of mechanical pulp. 120 mj can be set, and the interlayer strength is more preferably 90 to 110 mj.

Moreover, the suitable basic weight of the backing paper for wallpaper used is 40-150 g / m < ² >. When the basis weight is less than 40 g / m ² , it is difficult to obtain rigidity, strength, concealment and the like necessary for wallpaper. On the other hand, if the basis weight exceeds 150 g / m ² , it is excellent in rigidity, strength, and concealment, but on the other hand, the weight of the wallpaper increases, and excessive work is applied to the worker who pastes the wallpaper on the wall or ceiling. Will be. Moreover, since rigidity becomes high too much, the bonding suitability at the time of sticking a wallpaper to the corner part etc. of a room falls.

  The backing paper for wallpaper excellent in the present invention contains a filler so that the ash content is 5 to 18% by mass in order to obtain good resin foaming properties, strength, wallpaper peelability, dimensional stability and concealment. It is preferable to contain so that it may become ~ 15 mass%. When the ash content is less than 5% by mass, it becomes difficult to adjust the thermal conductivity of the obtained backing paper for wallpaper to a predetermined range, and the resin tends to cause poor foaming when processed into wallpaper. Moreover, in addition to being inferior in concealability, the interlayer strength tends to be high, leading to a problem that the peeling work efficiency at the time of reforming is lowered.

  Furthermore, it becomes difficult to obtain the dimensional stability necessary for wallpaper backing paper.

  The dimensional stability is obtained by adding a filler so that the ash content is 5 to 18% by mass, and preferably by drying the paper using a Yankee dryer, The elongation in water in the lateral direction (paper machine width direction) can be 0.8 to 1.5%, and the opening after the wallpaper is bonded to the wall can be prevented. Furthermore, the elongation in water is preferably 0.8 to 1.2%, and the number average fiber length of the disaggregated pulp of the backing paper for wallpaper which has been disaggregated according to JIS-P8220 is 0.8 to 2. High dimensional stability can be obtained by a method such as increasing the initial dewatering in the paper machine wire part, increasing the softwood pulp, and the like. In addition, when the underwater elongation in the lateral direction of the paper exceeds 1.5%, not only troubles such as opening of the paper will occur after the wallpaper construction, but also problems such as curling will occur at the time of construction, leading to a decrease in workability. This causes a problem.

  Also, in order to reduce the lateral water elongation of the paper to less than 0.8%, it is necessary to take excessive measures such as adding synthetic fibers and hardening the paper layer with resin, resulting in lower operability and higher costs. In addition, the quality is excessive as a general wallpaper backing paper, which is not economical.

  As the filler to be contained, known inorganic particles such as clay, talc, calcium carbonate, titanium oxide, and white carbon can be used. However, in the backing paper for wallpaper in the present invention, regenerated particle aggregates described in detail later. Is preferable from the viewpoint of obtaining good resin foamability.

  That is, when wallpaper is manufactured, a synthetic resin such as vinyl chloride resin or olefin resin is applied to the backing paper for wallpaper, and after preliminary drying at about 160 ° C, the resin is foamed in a heating furnace at about 230 ° C. It was found that foamability is greatly influenced by the thermal conductivity of the backing paper.

  Therefore, as a result of intensive studies focusing on this thermal conductivity, the present inventors preferably set the thermal conductivity to 0.2 to 0.5 W / (m · K) as the backing paper for wallpaper. It has been found that it is more preferable to set it to 0.3 to 0.5 W / (m · K).

  In order to set the thermal conductivity of the backing paper for wallpaper to 0.2 to 0.5 W / (m · K), the specific heat of the filler at a temperature of about 230 ° C. for drying and foaming the wallpaper resin is 1.2 J / g. It is preferable to use inorganic particles of / deg or less, and it is more preferable to use inorganic particles of 1.1 J / g / deg or less.

  If the specific heat at 230 ° C of the filler used is higher than 1.2 J / g / deg, it becomes difficult to set the thermal conductivity of the backing paper for wallpaper to 0.2 to 0.5 W / (m · K). Since the heat for foaming and drying the resin is hindered by the backing paper, it is difficult to be transmitted to the resin and the temperature rise of the resin is hindered, so it is not possible to obtain good foamability of resins such as vinyl chloride resin and olefin resin It is.

  In addition, since wallpaper of vinyl chloride resin-based wallpaper occupies about 90% of the market as wallpaper, the backing paper for wallpaper in the present invention is cheaper than expensive fired clay from the viewpoint of economy. It is preferable to use clay or a regenerated particle aggregate having a low specific heat and excellent in environmental protection and resource saving.

  As the regenerated particle aggregate, the particle constituents contain calcium, silicon, and aluminum in a mass ratio of 30 to 82: 9 to 35: 9 to 35 in terms of oxides, and particles of the regenerated particle aggregate Among the constituent components, a regenerated particle aggregate in which the total content ratio of the calcium, the silicon, and the aluminum is 90% by mass or more in the regenerated particle aggregate constituent component can be used.

  About the backing paper by the above manufacturing method, by making the content ratio of mechanical pulp and filler content within a certain range, while obtaining the required dimensional stability, concealment, and peeling workability at the time of renovation, Furthermore, the thermal conductivity can be adjusted to 0.2 to 0.5 W / (m · K), and the foaming property of the resin is improved by increasing the thermal conductivity of the backing paper to a certain range.

  Moreover, the regenerated particle aggregate that can be suitably used in the present invention preferably has an average particle diameter of 10 μm or less by the Coulter counter method from the viewpoint of concealment. When the average particle diameter exceeds 10 μm, the opacity decreases and it becomes difficult to obtain a desired concealing property.

  Moreover, it becomes easy to adjust the said interlayer intensity | strength (internal bond) to 70-120 mJ by the mixing | blending of these fillers. When the internal bond is lower than 70 mJ, the peeling work at the time of renovation becomes easy, but there is a possibility that delamination may occur due to an unintentional external force at the time of the wallpaper bonding work.

  Moreover, when it exceeds 120 mJ, the peeling work efficiency of the wallpaper at the time of remodeling falls.

  In the present invention, the wallpaper backing paper contains inorganic particles in an amount of 5 to 18% by mass, preferably by using clay or recycled particle aggregates as the inorganic particles, thereby improving the dimensional stability of the wallpaper backing paper, By setting the opacity according to JIS 8138 to 85 to 90%, and more preferably by setting the opacity to 90 to 92%, it is possible to obtain a backing paper with high concealment. When the filler content is less than 5% by mass, it is difficult to obtain a desired concealing property. Conversely, when the filler content exceeds 18% by mass, the rigidity and strength required for wallpaper backing paper are obtained. Becomes difficult.

  Therefore, in this invention, the thermal conductivity of the backing paper for wallpaper is 0.2 by containing 5-65 mass% of mechanical pulp in the pulp and including a filler so that the ash content is 5-18 mass%. It is one of the embodiments to set it to -0.5W / (m * K). Furthermore, it is one of the more preferable embodiments to use specific inorganic particles, specific specific heat, and inorganic particles having a particle size.

(Regenerated particle aggregate)
The regenerated particle aggregate that can be used in the present invention is described in detail below.

  In this embodiment, the deinked floss discharged from the used paper processing step is a main raw material, and is a regenerated particle aggregate obtained by subjecting the main raw material to a dehydration step, a drying step, a firing step, and a pulverization step. Calcium, silicon and aluminum are contained as particle constituents, and the mass ratio of these calcium, silicon and aluminum (calcium: silicon: aluminum) is 30 to 82 in terms of oxide in elemental analysis using an X-ray microanalyzer. : Recycled particle aggregates in which the total content of calcium, silicon and aluminum in the particle constituents is 90% by mass or more in terms of oxide can be suitably used. As described above, the regenerated particle agglomerates used in the present invention preferably have deinked floss discharged from the used paper processing step as a main raw material, and the main raw material is subjected to a dehydration step, a drying step, a firing step and a pulverization step. It is obtained by applying. In addition to these four steps, as will be described later, an aggregation step, a granulation step, a classification step provided between the steps, and the like may be provided. In addition, it is desirable that the production facility for the regenerated particle aggregate is provided with various sensors to control the state of the object to be processed and the equipment, the processing speed, and the like. Various flow paths such as a transfer flow path, a supply flow path, a discharge flow path, a circulation flow path, and a return flow path shown in the following specific description can be constituted by, for example, a pipe, a duct, or the like.

  Below, the manufacturing method of the reproduction | regeneration particle | grain aggregate which can be used for this invention using the deinking floss discharged | emitted from a used paper processing process (manufacturing process of a used paper pulp) as an example is illustrated. The deinking floss is an optimal example as a raw material for the regenerated particle aggregate, but other papermaking sludge such as papermaking sludge in the papermaking process can be used in combination with the deinking floss as the main raw material. Further, the following method is an example of a method for producing a regenerated particle aggregate, and is not limited to this method, and can be appropriately changed within a range not impairing the object of the present invention.

(1) Raw materials In the manufacturing process of used paper pulp, in order to continuously produce used paper pulp with stable quality, the used paper is selected and sorted, and used quality paper is used. The types, ratios, and amounts of these are basically constant. In addition, even if plastics such as films and sheets that cause fluctuations in unburned materials in the manufacturing process of recycled particle aggregates are contained in the waste paper as foreign matters, these foreign matters are deinked to obtain deinking floss. Can be removed in the previous stage. Therefore, when using deinked floss discharged from the waste paper pulp manufacturing process as a raw material, compared to the case of using sludge generated in other processes such as factory drainage process and papermaking raw material adjustment process as a raw material, Regenerated particle aggregates can be produced.

  The deinking floss referred to in the present specification means a material separated from pulp fibers in a used paper processing process for producing used paper pulp, mainly in a deinking process for removing ink adhering to the used paper.

(2) Dehydration step The deinking floss can be dehydrated by appropriately using known dehydration means such as a rotary screen. In the rotary screen, for example, the deinking floss dehydrated to 95 to 98% by mass is preferably dehydrated to 40 to 70% by mass with, for example, a screw press. Thus, if dehydration of deinking floss is performed in a multi-stage process and rapid dehydration is avoided, outflow of inorganic substances can be suppressed, and there is no fear that the flocs of deinking floss become too hard.

  During the dehydration treatment, an auxiliary agent that improves the dehydration efficiency, such as an aggregating agent that aggregates the deinking floss, may be added. In this case, an aggregating agent that does not contain iron may be used. preferable. When iron is contained, the whiteness of the regenerated particle aggregate may be reduced due to oxidation of iron.

  It is preferable in terms of production efficiency that the deinking floss dewatering process equipment is provided as a part of the regenerated particle agglomerate manufacturing process equipment. It is also possible to transport the deinking floss that has been performed.

(3) Drying step The dehydrated product obtained by dehydrating the deinking floss is transported to a constant supply device by a transporting means such as a truck or a belt conveyor, and is supplied from the quantitative supply device to the drying means.

  The drying means mainly includes, for example, a drying container to which a dehydrated product is supplied, a pair of rolls that are provided at the bottom of the drying container and scrapes the supplied dehydrated product, and hot air upward from between the pair of rolls. And hot air blowing means for blowing up. The hot air blowing means is configured such that a feed flow path is connected to the bottom of the drying container, and hot air is blown into the drying container through the feed flow path.

  As described above, the present drying means is large by loosening the dehydrated product with a strong and rough manner by a tangible means such as a pair of rolls, and in addition weakly and finely loosening with an intangible means such as hot air. -It is possible to stably control the moisture content and align grains of dehydrated products having various properties such as small, hard and soft.

  In particular, when the dehydrated product supplied into the drying container is dehydrated to a moisture content of 40 to 70% by mass, the temperature of the hot air is preferably 100 to 200 ° C, more preferably 120 to 180 ° C. Preferably, it is 130-170 degreeC. Thus, when the moisture content of the dehydrated product is 40 to 70% by mass, it can be sufficiently dried even with hot air at 100 ° C. On the other hand, the drying proceeds faster than the particle alignment of dehydrated materials having various properties such as large, small, hard, and soft, and the difference between the moisture content on the particle surface and the moisture content inside is made small and uniform. Therefore, the temperature of the hot air is preferably 200 ° C. or less.

  The drying of the dehydrated product is preferably performed so that the moisture content of the dried product before the firing step (firing step inlet) is 2 to 20% by mass, more preferably 3 to 15% by mass, It is particularly preferable that the content be 3 to 10% by mass. If the dehydrated product is dried to a range in which the moisture content is less than 2% by mass, there is a risk of over-burning in the subsequent firing step. On the other hand, if the dehydrated product is dried only to the extent that the moisture content exceeds 20% by mass, it may be difficult to perform firing reliably.

  The average particle size of the dried product is preferably 400 to 2000 μm, and more preferably 450 to 1900 μm. If the average particle size of the dried product before the firing process (firing process inlet) is too small, the firing proceeds too much at the time of firing, so the fired product may become extremely hard, and conversely if too large, Firing is difficult to reach to the core of the fired product, and carbides are likely to remain in the fired product, and the whiteness of the fired product may not increase.

  The particle size of the dried product is preferably adjusted so that the particle size of 355 to 2000 μm is 70% by mass or more, more preferably 75% by mass or more, and 80% by mass. It is particularly preferable to adjust so as to be above. When the dried product is manufactured so that the particle size of 355 to 2000 μm is 70% by mass or more, that is, when the dried product of small particles is removed, partial overheating is prevented, and the firing becomes more uniform. . Therefore, the possibility of practical use in terms of making the quality of the obtained regenerated particle aggregate uniform can be increased. Furthermore, when classification is performed after drying in this manner, dried particles having small diameters can be reliably removed, and the processing efficiency is also improved.

(4) Firing step The dried material that has fallen to the bottom inside the cyclone is increased in vigor by the exhaust fan provided in the middle of the transfer flow path and in the first half of the cyclone type. 1 sent to combustion furnace. In the first combustion firing furnace, particles are prevented from being refined by swirling and dropping the dried product, and the unburned rate is adjusted by firing in this process (first firing step).

  Firing in the first firing step is preferably performed such that the unburned rate is 5 to 30% by mass, more preferably 8 to 25% by mass, and 10 to 20% by mass. It is especially preferable to carry out. If the unburned ratio in the first firing step is less than 5% by mass, over-burning of the particle surface during firing occurs, the surface becomes hard, oxygen deficiency inside occurs, and the whiteness of the regenerated particle aggregate may decrease. There is. On the other hand, if the unburned rate in the first firing step exceeds 30% by mass, unburned matter may remain even after firing in the second firing step, and further prevents the unburned matter from remaining. For this reason, the surface of the regenerated particle aggregate may be hardened by burning and burning until the particle surface is overfired.

  Although there is no limitation in particular in the form of a 1st combustion baking furnace, For example, it is preferable that it is a cyclone type. According to the cyclone type, as described above, the unburnt rate can be more uniformly and reliably adjusted by suppressing the refinement of the particles.

  The fired product obtained in the first firing process is sent to the second combustion firing furnace and burned and fired (second firing process). As the second combustion firing furnace, for example, a known apparatus such as a rotary kiln furnace, a fluidized bed furnace, a stalker furnace, a cyclone furnace, a semi-dry distillation / negative pressure combustion type furnace, etc. can be used. A rotary kiln furnace that can be uniformly burned with stirring without applying excessive physical pressure in a small environment is preferable.

  In the firing in the first firing step and the second firing step, the temperature of the upper end portion of the first combustion firing furnace is set to 510 to 750 ° C., and the temperature in the second combustion firing furnace is set higher than the temperature of the upper end portion of the first combustion firing furnace. It is preferable to set it as low 500-700 degreeC, the temperature of the 1st combustion baking furnace upper end part shall be 550-730 degreeC, and the temperature in a 2nd combustion baking furnace is lower than the temperature of 1st combustion baking furnace upper end part 510- More preferably, the temperature at the upper end of the first combustion firing furnace is 580 to 700 ° C., and the temperature in the second combustion firing furnace is 550 to 660 ° C. lower than the temperature at the upper end of the first combustion firing furnace. It is particularly preferable that When the temperature of the upper end of the first combustion firing furnace is 600 to 680 ° C., and the temperature in the second combustion firing furnace is 580 to 650 ° C. lower than the temperature of the upper end of the first combustion firing furnace, the regenerated particles obtained Aggregates are more suitable as pigments. As described above, the temperature in the second combustion firing furnace is lowered by 10 to 50 ° C. lower than the temperature at the upper end of the first combustion firing furnace, so that the unburned material is burned while preventing over-burning of the particle surface. Can do.

(5) Grinding step The fired particles can be made into regenerated particle aggregates that can be used as fillers by finely pulverizing them to a necessary particle size in the grinding step.

  For example, particles obtained by firing are pulverized using a dry pulverizer such as a jet mill or a high-speed rotary mill, or a wet pulverizer such as an attritor, a sand grinder, or a ball mill, and the desired regenerated particle aggregate It can be. When the regenerated particle aggregate is used as a filler for internal addition, it is preferable to adjust the average particle size by a Coulter counter method to 0.1 to 10 μm.

(6) Auxiliary process When the quality of the regenerated particle aggregate is required to be further stabilized, it is preferable to classify the particle size of the regenerated particle aggregate uniformly in each step. It is desirable to feed back to the previous process.

  In addition, it is preferable to granulate the deinked floss that has been subjected to dehydration in the previous stage of the drying process, more preferably to classify the granulated product uniformly, and coarse granulated particles. Further, the quality can be further stabilized by feeding back the fine granulated particles to the previous process. In addition, a well-known granulation equipment can be used for granulation, for example, rotation, a stirring type, an extrusion type, etc. are suitable.

  Further, it is preferable to remove foreign matters other than the regenerated particle aggregates. For example, in the manufacturing process of waste paper pulp, sand, plastic foreign matters, metals, etc. are removed with a pulper, screen, cleaner, etc. before the deinking step. Is preferable in terms of removal efficiency. In particular, iron content may reduce the whiteness of the regenerated particle aggregate by oxidation, and therefore it is preferable to avoid iron content and selectively remove it. The equipment in each process is designed or lined with materials other than iron to prevent iron from being mixed into the system due to abrasion, etc., and high magnetic materials such as magnets are selectively installed in the drying / classifying equipment. It is preferable to remove iron.

In the drying step, the firing step, and, if necessary, the classification step, it is preferable that the particles having a particle size of 40 μm or less are preliminarily processed to 90% by mass or more before the pulverization step. Accordingly, a single-stage pulverization process by wet pulverization can be performed without performing a multistage pulverization process such as pulverization of coarse particles by dry pulverization and fine particle formation by wet pulverization. Thereby, the peak height of the average particle diameter in the differential curve of the particle size distribution by the Coulter counter method can be set to 30% or more. Furthermore, the pore volume of the regenerated particle aggregate is adjusted to 0.15 to 0.60 mL / g by adjusting calcium, silicon and aluminum in the deinking floss as the main raw material in advance, for example, to a mass ratio described later. The pore surface area may be 10 to 25 m ² / g, and the pore radius may be 30 to 100 nm.

  Thus, deinked floss discharged from the waste paper pulp manufacturing process is used as a main raw material, and the regenerated particle aggregate is obtained by subjecting the main raw material to a dehydration process, a drying process, a baking process, and a pulverization process. In the invention, as the regenerated particle aggregate, a silica-coated regenerated particle aggregate in which the surface of the particles obtained through the above-described steps is further coated with silica can be particularly preferably used.

  Silica is further precipitated on the surface of the regenerated particle aggregate to form a silica-coated regenerated particle agglomerate, which is used for paper making as a buffering agent or a bleaching aid by reacting with sodium hydroxide in the used paper processing step in circulation use. This can contribute to the recycling of raw materials and inorganic particles.

  In addition, the deinking floss discharged from the used paper processing step used in the present invention has a tendency to increase the content of calcium carbonate with the recent neutral paper making, and the amount of calcium in the regenerated particle aggregate obtained is increased. The ratio also tends to be high. Thus, when the regenerated particle aggregate having a high calcium ratio is internally added to the pulp, the opacity of the paper may be slightly lowered. However, the silica-coated regenerated particle aggregate having silica deposited on the surface is used for papermaking. The function as a regenerated particle aggregate is very high, and the opacity of the backing paper for wallpaper obtained by internally adding the silica-coated regenerated particle aggregate to pulp is improved.

  The silica covering the surface of the regenerated particle aggregate can be used without particular limitation as long as it is not naturally produced silica but synthetic silica by some chemical reaction. Specific examples include colloidal silica, silica gel, and anhydrous silica. These synthetic silicas make use of excellent properties such as high specific surface area, high gas adsorbing capacity, fineness, permeability to pores and large adsorbing power, high adhesion, and high oil absorption. It is used in a wide range of fields. Among these, colloidal silica has a shape such as a spherical shape, a chain shape, and an amorphous shape, in which impurities are removed from a silicic acid compound to form an anhydrous silicic acid sol, and the sol is stabilized by adjusting pH and concentration. Amorphous silica. Silica gel is hydrous silicic acid obtained by decomposing sodium silicate with an inorganic acid. Anhydrous silica is obtained by hydrolysis of silicon tetrachloride.

  There is no particular limitation on the method for obtaining silica-coated regenerated particle aggregates by precipitating silica on the surface of the regenerated particle aggregates. For example, the following methods can be suitably employed. First, regenerated particle aggregates are added and dispersed in an alkali silicate solution, and after preparing a slurry, while heating and stirring, an acid is added while maintaining the liquid temperature at about 70 to 100 ° C. to produce a silica sol. Subsequently, silica can be deposited on the surface of the regenerated particle aggregate by adjusting the pH of the final reaction solution to a range of 8-11. Silica deposited on the surface of the regenerated particle aggregate in this way reacts at a high temperature with a dilute solution of mineral acid such as sulfuric acid, hydrochloric acid, nitric acid, etc., using alkali silicate (eg, sodium silicate: water glass) as a raw material. And silica sol particles having a particle size of about 10 to 20 nm, which are obtained by hydrolysis reaction and polymerization of silicic acid.

  In addition, silica sol fine particles with a particle size of several nanometers, which are generated by adding an acid such as dilute sulfuric acid to an alkali silicate solution such as sodium silicate solution, cover the entire porous surface of the regenerated particle aggregate. The surface of the regenerated particle aggregate is caused by the bond between the silica sol fine particle on the surface of the inorganic fine particle and the silicon, calcium, or aluminum included in the regenerated particle aggregate accompanying the crystal growth of the silica sol fine particle. Silica can also be deposited on the substrate. In this case, the pH when adding the acid to the alkali silicate solution is in a neutral to weakly alkaline range, and the pH is preferably adjusted in the range of 8-11. This is because if the acid is added until the pH reaches an acidic condition of less than 7, white carbon may be generated instead of silica sol particles.

The type of the alkali silicate solution is not particularly limited, but a sodium silicate solution (No. 3 water glass) is particularly desirable from the viewpoint of easy availability. The concentration of the alkali silicate solution is such that the silica component in the regenerated particle aggregate decreases and the silica content (SiO _{2) in the} solution does not become difficult to precipitate on the surface of the regenerated particle aggregate. (Converted) is preferably 3% by mass or more, and the silica deposited on the surface of the regenerated particle aggregate becomes white carbon from the form of the silica sol, which impairs the porosity of the regenerated particle aggregate and improves opacity. In order to eliminate the possibility that the effect is insufficient, the silicic acid content (in terms of SiO ₂ ) is preferably 10% by mass or less.

  The regenerated particle aggregate thus obtained contains calcium, silicon and aluminum as particle constituents, and these calcium, silicon and aluminum form a composite in the particles. The mass ratio of these calcium, silicon and aluminum in the regenerated particle aggregate (calcium: silicon: aluminum) is determined by X-ray microanalyzer (model number: E-MAX S-2150, Hitachi, Ltd./Horiba, Ltd.). In the elemental analysis using the product, 30 to 82: 9 to 35: 9 to 35, preferably 40 to 82: 9 to 30: 9 to 30, particularly preferably 60 to 82: 9 to 30 in terms of oxide. 20: 9-20. In particular, when the regenerated particle aggregate is a silica-coated regenerated particle aggregate, the mass ratio of calcium, silicon, and aluminum (calcium: silicon: aluminum) is determined by elemental analysis using the X-ray microanalyzer. In terms of oxide, it is 30 to 62:29 to 55: 9 to 35, preferably 30 to 50:35 to 55:15 to 30. At the same time, the total content of calcium, silicon and aluminum in the particle constituents is 90% by mass or more, preferably 94% by mass or more in terms of oxides in the same elemental analysis as described above.

  Thus, since the regenerated particle aggregate contains calcium, silicon, and aluminum as the particle constituents in terms of oxides in the mass ratio, the specific gravity is light and excessive aqueous solution absorption is suppressed, Dehydration in the dehydration process is good and moisture adjustment in the drying process is easy, as well as reducing the proportion of unburned material in the firing process and reducing the risk of excessive hardness due to sintering. it can.

  In order to adjust the mass ratio of calcium, silicon and aluminum in the regenerated particle aggregate within the above range in terms of oxide, for example, it is originally preferable to adjust the raw material composition in the deinking floss, but the drying process or firing In the process, and further in the classification process as necessary, it is also possible to adopt a method of containing a coating floss having a clear origin or an adjustment process floss by spraying or a method of containing incinerator scrubber lime.

  For example, to adjust the calcium content in recycled particle aggregates, neutral papermaking wastewater sludge and wastewater sludge from the coated paper manufacturing process, to adjust the silicon content, increase opacity. To adjust the aluminum content of newsprint manufacturing wastewater sludge, which is added in large quantities as an additive, a large amount of papermaking wastewater sludge using acid band such as acid papermaking and clay is used. The drainage sludge from the fine paper making process can be used as appropriate.

  Moreover, in order to adjust the total content ratio of calcium, silicon and aluminum to 90% by mass or more in terms of oxide, for example, means for using a flocculant containing no iron in the agglomeration treatment of drainage sludge, Designing or lining the manufacturing equipment process with materials other than iron to prevent iron from entering the system due to wear, etc.Furthermore, high magnetic materials such as magnets are installed in the drying / classifying equipment to reduce the iron content. It is possible to adopt a means for removing. In particular, iron content is preferably a causative substance that lowers the whiteness by oxidation, and thus is preferably removed selectively.

  By the way, calcium carbonate has homogeneous images such as hexagonal calcite crystals (calcite) and orthorhombic aragonite crystals (aragonite). Most limestones produced in nature are calcite crystals, and shellfish contain aragonite crystals in addition to calcite crystals. Furthermore, although not natural, calcium carbonate also has vaterite crystals. There are various kinds of calcium obtained from the deinking floss, but it becomes a substantially uniform calcium carbonate property by calcination and aggregation. Therefore, the calcium contributes to the quality stability of the regenerated particle aggregate itself, and the regenerated particle aggregate is an agglomerate composed of particles in which different components such as calcium, silicon and aluminum are combined, Shows stable properties.

  In addition, the regenerated particle aggregate contains silicon as a particle component, but the silica particles composed of the silicon are fine, so that the optical refractive index is high. By using such a regenerated particle aggregate containing 9 mass% or more of silicon in terms of oxide as a filler, the opacity of the resulting wallpaper backing paper is further improved.

  That is, the regenerated particle agglomerates thus obtained have one characteristic in that they are composed of agglomerates in which different components such as calcium, silicon and aluminum are agglomerated, because they have a small specific heat, and are excellent in opacity and water absorption. When it is contained in the backing paper for wallpaper, it is possible to obtain a backing paper for wallpaper that is particularly excellent in resin foaming property, dimensional stability, and concealment property and excellent in wallpaper peeling workability at the time of reforming.

  Next, specific examples of the present invention will be described.

Common matters in Examples 1 to 6 and Comparative Examples 1 to 4

  In order to confirm the effect of the backing paper for wallpaper according to the present invention, the following various samples were prepared, and a test for evaluating the quality of each sample was performed. In addition, in a present Example, the numerical value which shows a mixing | blending, a density | concentration, etc. is a numerical value of the solid content or the mass reference | standard of an active ingredient. Moreover, since the pulp, chemical | medical agent, etc. which are shown in a present Example are only examples, it cannot be overemphasized that this invention is not restrict | limited by these Examples, and can be selected suitably.

To compare with the 6 type of paper according to the present invention (to no "Example 1" This is referred to as "Example 6"), and these Examples 1 through 6, the four types of paper (which Are referred to as “Comparative Example 1” to “Comparative Example 4 ”).

[Examples 1 to 6 ]
After blending 20% by weight of softwood bleached kraft pulp (NBKP), 40% by weight of hardwood bleached kraft pulp (LBKP) and 40% by weight of mechanical pulp (BTMP) as a pulp material for wallpaper backing paper , The type and addition amount are as shown in Table 1, the sulfuric acid band is 2.5% by mass, the sizing agent (trade name: E-3600, manufactured by Modern Chemical Co., Ltd.) is 1.0% by mass in terms of solid content, and dry paper 0.3% by mass of a power enhancer (trade name: DS-4360, manufactured by Seiko PMC Co., Ltd.), and a wet paper strength enhancer (WS4024, epichlorohydrin manufactured by Seiko PMC Co., Ltd.) converted to solids The raw material slurry was adjusted by adding 0.5 mass%. This raw material slurry was paper-made with a long paper machine equipped with a Yankee dryer, and a backing paper for wallpaper having a basis weight of 65 g / m ² was obtained.

  When the wallpaper backing paper was disaggregated according to JIS-P8220, the number average fiber length of the disaggregated pulp was 1.2 mm.

  In addition, “specific heat” of each filler for internal addition in Table 1 is specific heat at a temperature of 230 ° C.

[Comparative Examples 1-2]
A wallpaper backing paper obtained in the same manner as in Example 1 except that the content of the raw material pulp is as shown in Table 1.

[Comparative Examples 3 to 4 ]
The backing paper for wallpaper obtained in the same manner as in Example 1 except that the type and amount of filler for internal addition are as shown in Table 1.

[Comparative Example 5 ]
Evaluation was conducted in the same manner as in the Examples with respect to 60 g / m ² of general bleached glazed kraft paper commercially available.

[Comparative Example 6 ]
Evaluation was made in the same manner as in the example with respect to a commercially available general copy paper of 64 g / m ² .

  “Specific heat (230 ° C. specific heat: J / g / deg)” in Table 1 is 100 to 100 in differential scanning calorimetry (DSC) using a thermal analyzer manufactured by Seiko Instruments Inc. according to JIS-K7123. It is a value of 230 ° C. in which the specific heat change amount is measured in the range of 250 ° C.

  The “ash content (%)” is a value obtained by measuring the ash content when combusted at 525 ° C. according to JIS-P8252.

  “Thermal conductivity (W / (m · K))” is a value measured by a heat flow meter method using a thermal conductivity meter manufactured by Kyoto Electronics Industry Co., Ltd. according to JIS-A1412-2. . The measurement was performed under the condition of a temperature of 20 ° C.

  “Polyvinyl chloride resin foaming” means that a vinyl chloride paste is applied to a thickness of 100 μm with a table blade coater, pre-dried at 160 ° C., and then foamed in a heating furnace at 230 ° C. to obtain a prototype vinyl wallpaper. The foamability was evaluated. “◎” indicates that foamability is very good, “◯” indicates that there is no problem, “Δ” indicates that foamability is slightly poor, and “×” indicates that foamability is poor and cannot be used as a backing paper.

  “Tensile strength (longitudinal) (kN / m)” is a value in the longitudinal direction (flow direction) measured by “Testing method of paper and paperboard—tensile properties” defined in JIS-P8113.

  “Interlaminar strength (mJ)” refers to JAPAN TAPPI No. It is a value measured by the internal bond tester method specified in 18-2.

  “Wallpaper peelability” refers to a prototype vinyl wallpaper in which vinyl chloride paste is applied to wallpaper backing paper, starch paste is applied to the backing paper surface, and then applied to a plywood board for 3 days at 23 ° C., 50% R / After standing under the condition of H, the delamination property when peeled from the plywood board and the remaining way of the backing paper for wallpaper remaining on the plywood board were observed. “◎” indicates that the release peels uniformly between the paper layers, “○” indicates that the release does not occur without problem, and part of the backing paper remains on the resin side, and part of the backing paper remains on the plywood side, and peels unevenly. It was set as “x”.

  “Elongation in water (lateral)” is a value measured according to the J · TAPPI-No. 27-28A method.

  “Wall paper opening” means that a trial vinyl wallpaper coated with vinyl chloride paste is cut into a rectangle with the long (flowing) direction of the backing paper as the long side, and starch paste is applied to the surface of the backing paper. The two papers are pasted on a plywood board so that the long sides do not overlap each other and do not overlap, and then left for 3 days at 23 ° C. and 50% R / H. The presence or absence was confirmed. “◎” indicates that there is no opening, “◯” indicates that there is no problem, and “×” indicates that the opening is large.

  “Opacity (%)” is a value measured by “paper and paperboard—opacity test method (backing of paper) —diffuse illumination method” defined in JIS-P8149.

  “Concealment” refers to a prototype vinyl wallpaper in which vinyl chloride paste is applied to wallpaper backing paper, starch paste is applied to the backing paper surface, and then applied to a plywood board for 3 days at 23 ° C., 50% R / H. Then, the wallpaper was visually evaluated for the concealment property of the wallpaper. Those with excellent concealment were marked with “◎”, those with no problem were marked with “◯”, and those with poor concealment and impaired commercial value were marked with “X”.

Evaluation The backing paper for wallpaper according to the present invention is a backing paper for wallpaper formed by a paper machine using pulp and filler as a main raw material as shown in claim 1, wherein the pulp contains mechanical pulp Is contained in an amount of 5 to 65% by weight, the filler is contained in an amount of 5 to 18% by weight as the ash content of the wallpaper backing paper, and the thermal conductivity is 0.2 to 0.5 W / (m · K). The wallpaper backing papers of Examples 1 to 6 satisfying all of these conditions are excellent in various physical properties such as PVC resin foaming property, wallpaper peeling property, wallpaper opening, and concealing property. Evaluation (◎ or ○ evaluation) was obtained. On the other hand, the backing paper for wallpaper of Comparative Example 1 having a mechanical pulp content lower than the conditions in claim 1 is inferior in wallpaper peelability and hiding properties (x evaluation), and the mechanical pulp content in claim 1 The backing paper for wallpaper of Comparative Example 2, which has more conditions than the above, was inferior in PVC resin foamability and wallpaper opening (x evaluation). Moreover, even if it is a filler of a predetermined specific heat, the backing paper of Comparative Examples 3 and 4 in which the internal filler is less than the conditions in claim 1 is PVC resin foaming property, wallpaper peeling property, wallpaper opening, hiding property Both results were inferior (x evaluation).
In addition, a commercially available bleached piece glossy kraft paper was evaluated as Comparative Example 5 for reference, but the results were inferior in PVC resin foaming property, wallpaper peelability, and wallpaper opening (× evaluation), and the difference from the product of the present invention was clear Met.

For reference, a commercially available high quality paper was evaluated as Comparative Example 6 , but the results were inferior in wallpaper peelability and wallpaper opening (× evaluation), the difference from the product of the present invention was clear, and the backing for wallpaper It was not usable as paper.

Claims (2)

Wallpaper backing paper with pulp and filler as main ingredients,
The pulp contains 5 to 65 mass% mechanical pulp,
The filler is contained so that the ash content of the backing paper for wallpaper measured according to JIS-P 8252 is 5 to 18% by mass,
As the filler, a regenerated particle aggregate obtained by dehydrating and drying, firing, pulverizing, and agglomerating in the firing process, using the deinking floss generated in the deinking process of the waste paper processing process for producing waste paper pulp as the main raw material Is used,
A wallpaper backing paper, wherein the wallpaper backing paper has a thermal conductivity of 0.2 to 0.5 W / (m · K), measured according to a heat flow meter method of JIS-A1412-2.   2. The wallpaper backing paper according to claim 1, wherein the filler is inorganic particles having a specific heat measured in accordance with JIS-K7123 at a temperature of 230 [deg.] C. of 1.2 J / g / deg or less.