DE602004000712T2 - Interlayer paper for glass and glassy sheet materials - Google Patents

Abstract

Inserting paper for clean glass-like sheet materials reducing transport and storage costs without relying on packaging spacers, preventing paper marks, and providing electrostatic adhesion, comprised of a nonwoven sheet made from regenerated cellulose obtained by the viscose process, cuprammonium process, or other cellulose regenerating process, in particular one suppressed in content of hot water solubles (heat water soluble ingredients) to less than 0.1 wt% per unit nonwoven sheet, wherein the nonwoven sheet is formed so that the regenerated cellulose fibers are fused through fused parts without use of a binder and the surface of the nonwoven sheet is treated for dust prevention by for example pressing by a flat roller, suction by a suction system, etc. The obtained nonwoven sheet may be supercalendered. <IMAGE>

Description

BACKGROUND THE INVENTION

1st area the invention

The The present invention relates to an inserter paper for interposing glassy sheet materials at the time of transport or storage of such glassy sheet materials inserted to in particular, it continues to refer to an insert paper, the contamination on the glass surface through the insert paper even reduced, and on suppressing the generation of dust.

2. Description of the stand of the technique

Usually is at the time of transport or storage of flat glass or other glassy Layer materials or sheets of paper between the glassy layer materials inserted, to improve handling. In the conventional insert paper, in particular insert paper, made of recycled paper, responds at the time of transport and storage the moisture on the surface of the glass (moisture in the air) with the alkaline components of the glass, around the To ate glass and to cause a surface deterioration. Further become the ink that is contained in the recycled paper, and the Resin components derived from recycled paper material itself are on the glassy ones Transfer layer materials, around paper stains on the surface of the glassy one To cause layered materials.

Around the surface deterioration and paper stains observable at the time of using conventional insert paper, to prevent, were an insert paper with dispersed, cut holes (e.g., the Japanese Patent publication (A) No. 5-208841), insert paper, in the zeolite in the papermaking process (e.g. Japanese Patent Publication (A) No. 7-41034), insert paper, that on its surface with a water-soluble Resin coated (e.g., Japanese Patent Publication (A) No. 9-170198), and insert paper, that in the hot water solubility is set (e.g., Japanese Patent Publication (A) No. 2003-41498), developed. Improvements have been made in terms of hygroscopic Property, the contact surface the surface and other physical properties, and These papers are used so far.

at the glass-like Flat materials used as substrates for flat panel displays (FPD) like liquid crystal displays (LCDs), plasma display panels (PDPs), and organic EL displays however, a much higher surface cleanliness is required. Indeed, even using the above types of insert paper, it was difficult Dirt on the glass surface to prevent to a required degree. Therefore, at the present time this not for the transport or storage of "glass substrates" supplied to the display manufacturers, used. They are only used for "glass layers" that are later added thin films coated to produce the glass substrates.

Therefore, when transporting or storing glass substrates for display manufacturers, becomes common Use made of the procedure of transport and storage while maintaining the glass-like sheets by plastic packaging spacers (e.g., Japanese Patent Publication (A) No. 2000-142873). With this method it is possible the glass-like ones To keep flat materials from sticking together. It is also effective across from Pollution on the surface the glass-like Flat materials. However, the packaging spacers with wasted space between the glass-like layer materials connected. There was therefore the problem that it was only possible a small number of glass-like ones To transport or store flat materials all at once - which too higher Cost of logistics and storage leads.

JP 2003-041498 A describes a spacer paper suitable for pasting between Glass plates, where the distance paper is made of mechanical, garbage waste paper as raw material, and a portion of in hot Water soluble Substances in the range of 0.1 to 0.7 wt .-% has.

JP 05-208841 A describes a layer paper for glass with notched perforations, the above the entire surface are dispersed.

JP 2000-154492 A describes an impregnated paper, suitable as an intermediate paper or wrapping paper, carried in a clean air space, especially as an intervening Pa Pier for a connection frame. This impregnated paper is obtained by impregnating a base paper with a binder. The impregnated paper has ≤ 0.02 ppm content of respective ions of all kinds extracted when extracting 1 g of the impregnated paper with 70 ml of deionized water at 100 ° C for one hour based on 1 cm ^{2 of} the impregnated paper becomes.

SUMMARY THE INVENTION

A The object of the present invention is an insert paper for clean, glasslike To provide flat materials that reduce the cost of transportation and reduces storage without relying on packaging spacers to leave to prevent paper stains and an electrostatic adhesion to enable.

To the Achieving the above object will be an insertion paper for glass-like Sheet materials as defined in claim 1, comprising a nonwoven sheet made of cellulose, wherein a proportion of in hot Water soluble Fabrics in the nonwoven sheet measured based on "TAPPI T207 om-81, Water Solubility of Wood and Pulp, 6.2. Hot Water Solubility, less than 0.1 Wt .-% is. Because the paper is made from a nonwoven sheet made of cellulose, the inclusion of constituents, which are different from cellulose, which is made up in insert paper conventional pulp, or insert paper, coated with resin, observed, eliminated. As a result can the proportion of in hot Water soluble substances be reduced to less than 0.1 wt .-%. This is extremely effective while suppressing of contamination on the glass surface during transport or the Storage (paper stains).

The Nonwoven sheet is produced without using a binder. Since no binder is used in the production of the nonwoven sheet becomes, the insert paper becomes Made from only cellulose (regenerated cellulose), and transmission of impurities etc., contained in the glass surface, what in conventional insert paper is observed can be eliminated. As a result, it is possible to still one bigger effect while suppressing to achieve contamination on the glass surface (paper stains) so that a transport and storage of glass-like flat materials in allows an extremely clean state becomes.

Preferably The nonwoven sheet is pressed through a flat roller. Since that Nonwoven sheet is pressed through a flat roller, it becomes possible, to suppress the generation of dust when the insert paper, made of the nonwoven sheet, is used.

Further Preferably, the nonwoven sheet is supercalendered. Because the nonwoven sheet Supercalendered, it allows the generation of dust to suppress, if the insert paper, made of the nonwoven sheet, is used. Because the smoothness of the surface of the nonwoven sheet is improved, the adhesion between the insert paper (Nonwoven sheet) and the glass-like Improves sheet materials using static electricity and the work of pasting of the insert paper between the glass-like ones Flat materials is facilitated.

Yet more preferred is a surface roughness of the nonwoven sheet not more than 1.5 μm as measured by a KES-FB-4S Surface tester. Because the surface roughness less than 1.5 μm is, is it is possible a good electrostatic adhesion with the glass-like ones To obtain flat materials.

SUMMARY THE DRAWINGS

These and other objects and features of the present invention more clearly apparent from the following description of the preferred Embodiments, with reference to the attached drawings, in which:

1 Fig. 10 is a sectional view of a spun fiber according to an embodiment of the present invention;

2 Fig. 4 is a partially enlarged view of a nonwoven sheet according to an embodiment of the present invention; and

3 Fig. 10 is a schematic sectional view of an example of an intake system used for the dust-preventing treatment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment The present invention will be described below in detail with reference to the accompanying drawings described.

The inserting paper for glass-like Sheet materials of the present invention is a nonwoven sheet, made of cellulose, in particular one in which the proportion of in hot Water soluble substances (in hot Water soluble Constituents) to less than 0.1% by weight of the unit nonwoven sheet repressed becomes. Next is in the insert paper for glass-like Sheet materials of the present invention, the material manufactured cellulose, to a nonwoven sheet without the use of a binder formed, and the surface of the nonwoven sheet is suitably treated to remove dust or supercalendered, as described in detail later.

The "cellulose" in the present Invention is cellulose obtained from pulp made from cotton, Wood chips, etc., by alkaline dissolving, etc. using the Viscous method, the copper ammonium method or other known Cellulose regenerating process (so-called "regenerated cellulose") .This regenerated Cellulose closes a fibrous one Rayon (viscose) and copper ammonium (copper ammonium). As the above mentioned Rayon or other regenerated cellulose for the nonwoven sheet material of the present invention, this differs Paper from insert paper, made by recycled paper, and insert paper made by Wood pulp, etc., and it is in the uniformity of the ingredients contained elevated.

At the Create insert paper for glass-like Sheet materials as a woven sheet of the above-mentioned fibrous rayon or cuprammonium cellulose, it is generally necessary to use the rayon or the cuprammonium cellulose fibers with a lubricating oil in the Weaving machine, and therefore, the completed, woven sheet has a residual oil or others Impurities. Therefore, especially when painting the applicability for the Transport etc. of glass substrates for flat panel displays (FPDs), is pollution on the surface Glass substrates due to residual oil is a problem. Furthermore, at Using a conventional, woven layer made from Rayon or cuprammonium cellulose fibers as insertion paper for glass-like Flat materials, is the removal of the oil from the woven sheet itself required in a separate manner, allowing the processing method gets complicated and costs increase. Accordingly, the inserting paper for glass-like Flat materials suitably made of a nonwoven sheet, made of cellulose.

At the Producing the nonwoven sheet also has the method of adding various ones known binder for fibrous Cellulose. However, in view of the object of the present invention, the pollution on the surface the glass-like Flat materials as good as possible to suppress, should a nonwoven sheet produced without using a binder, be used. As a method of preparation under non-use a binder, the needle punching method of punching Pre-spun rayon or cuprammonium cellulose fibers by needling, to confuse them, etc., are called, but the needles must be in suitably coated with a lubricating oil. Therefore, will this for the same reasons as preferred when using a weaving machine.

Under The above aspect is as a method of manufacturing under Non-use of a binder means a manufacturing process such as the spunlace process, the adjacent fibers of preformed Rayon confused, copper ammonium cellulose etc. by high-pressure jets of water, used to make a nonwoven sheet, made from regenerated cellulose. Furthermore, for rayon the process of continuously spinning a fiber solution (viscose) and the adhesion of the fibers to each other by hot pressing to produce the nonwoven sheet, and, for cuprammonium cellulose, the process of continuous adhesion by hydrogen bonding, using the surface swellability of active fibers in the unregenerated state (blue thread), and the Entangling the fibers by high pressure jets of water around the Nonwoven sheet produce.

The "hot-water-soluble materials" in the present invention are the ingredients that dissolve in hot water, expressed as a percentage of the total weight of the nonwoven sheet As described in the background section, at the time of shipment and storage Glass-like sheets absorb moisture in the air through the insert paper, therefore, staining on the glass surface due to leaching of the ingredients in the insert paper has been considered a problem, therefore, the proportion of hot water-soluble substances (hot-water soluble ingredients) used as an indicator for determining the leaching of ingredients of the insertion paper.

The in hot Water soluble Fabrics in the present invention as detailed in the later-mentioned example are measured based on "TAPPI T207 om-81, Water Solubility of Wood and Pulp, 6.2. Hot Water Solubility ", produced by the Technical Association of the Pulp and Paper Industries (TAPPI). As in the Japanese Patent publication (A) No. 2003-41498, disclosed in the section of the prior art, It was described in the insert paper for glass-like Layered materials obtained by a process of recycled paper is made extremely difficult considers the proportion of in hot Water soluble Reduce substances to less than 0.1% by weight. In contrast to uses the present invention as described later Example becomes clear, cellulose as material and contains almost no other impurities, thus it is possible to reduce the proportion of soluble in hot water Reduce substances to less than 0.1% by weight. This is considered effective considered while preventing paper stains on the surface of glasslike Flat materials (in particular glass substrates).

At the Obtained a nonwoven sheet made of regenerated Cellulose, the description is with reference to a nonwoven sheet given by the viscose method.

Fibers (cellulose) obtained from cotton, pulp, etc. are reacted with carbon disulfide in the presence of an alkaline substance to produce viscose. This is spun in a spun bath containing formaldehyde or another methylolating agent, a spun fiber 10 comprising three layers shown in the sectional view of FIG 1 ie cellulose 11 Hydroxymethyl cellulose exanthate (hereinafter referred to as "HMCX") 12 , and sodium cellulose xanthate (hereinafter referred to as "NaCX") 13 ,

The general chemical structures of the three components of the above woven fiber 10 are shown in Table 1.

Table 1

The above woven fiber 10 Three layers are suitably cut, dispersed and processed to form a substantially planar material. By hot pressing at the time of embossing using a coining roll in the presence of moisture, the HMCX is heat-liquefied and nearby spun fibers are fused together. Upon further heating, the HMCX breaks down and is changed to cellulose to the fused parts 21 shown in the partially enlarged view of 2 , and solidifies. Thereafter, the material is shrunk at an appropriate temperature and pH in the presence of a weak acid, thereby converting the above-mentioned HMCX and NaCX to cellulose. Next, the material is bleached, rinsed, dried, etc., creating a nonwoven sheet 20 made of cellulose, and produced without using a binder. reference number 22 shows the regenerated cellulose that has been internally converted to cellulose.

As described above contains the present invention for glasslike Sheet materials of the present invention Cellulose derivatives in their production processes, but these eventually become cellulose converted, so that one can say that cellulose their material is.

To the Time of producing the nonwoven sheet, in particular for Time of embossing, It is preferred to press the material further through a flat roll. When using a flat roller in this way, the spun Fibers, fused by the embossing, continue through the flat Roller pressed to smooth the material, while linting to keep the short woven fibers low. Therefore, the pressing is Effective through the flat roller as a treatment for avoiding dust. It It should be noted that the shape and size of the embossing, the amount of pressing be selected by the flat roller, etc. in a suitable manner can.

In addition, the nonwoven sheet obtained by the complete conversion of the internal components of the spun fiber into cellulose, and bleaching, rinsing, drying, etc., sometimes treated to prevent dust, is sucked by sucking the fluff on the surface of the nonwoven sheet Using the intake system 30 shown in the schematic sectional view of 3 for example, at the time of taking out after drying. The intake system 30 blows air, fed a pressure holder 32 , to the surface of the nonwoven sheet 20 , transmitted by a transfer roller 45 while the surface of the nonwoven sheet is caused to vibrate by applying ultrasonic waves from an ultrasonic wave generator 33 to the dust-generating factors of the nonwoven sheet 20 to liberate it, it sucks in the suction unit 31 , and it sucks them outward from the suction port 35 , 3 Figure 14 shows an example of the suction of dust generating factors from one side of the nonwoven sheet 20 but it is preferred to soak up the dust-generating factors from both surfaces of the nonwoven sheet. reference number 34 is a suction port, whereas 40 is a surge of static electricity.

in the Generally, as a mode of using insert paper, used for glass-like flat materials, as disclosed in Japanese Patent Publication (A) No. 49-13865, at least one of the insertion papers and the glass-like Flat material charged with a specified voltage, and the static electricity, generated at this time, is used to connect these two together to stick. This means, static electricity is used to insert the insert paper and the glass-like To cause flat material to stick together to work of insertion of the insert paper in the glass-like To facilitate flat materials.

Indeed is the surface of the nonwoven sheet rougher in surface shape, even compared with conventional insert paper. Therefore, the contact surface between the glass-like Sheet and the nonwoven sheet smaller than that of the conventional Inserting paper, and you can not say that has a sufficient effect of improvement the adhesion is obtained by the electrostatic charging. Accordingly, one can say that it is preferred the smoothness of the nonwoven sheet as much as possible to improve the adhesion the nonwoven sheet and the glass-like sheet to improve, while charging these with static electricity.

Therefore, in order to improve the smoothness of the surface of the nonwoven sheet produced as described above and treated to avoid dust, supercalendering is performed. The above supercalendering is usually performed by passing the nonwoven sheet of the present invention through multiple stages of a sum of 5 to 20 stages of alternating metal rolls and non-metallic elastic rolls, and pressing by a linear pressure of 1900 to 2600 N / cm (maximum about 3500 N) /cm). As a result of supercalendering, the nonwoven sheet is subjected to high pressure and becomes thinner. At this time, generation of dust from the surface of the nonwoven sheet is reduced, and the smoothness is also increased. It is to be noted that the pressure (linear pressure), temperature, moisture content of the nonwoven sheet, pressing time, and other treatment conditions in supercalendering are suitably set.

in this connection becomes the smoothness of the nonwoven sheet of the present invention defined as the surface smoothness of the Nonwoven sheet (insert paper for glass-like Flat materials). The surface roughness is quantified in the measurement by a KES-FB-4S surface tester, manufactured by KES Co., and is suitably no more than 1.5 μm, preferably not more than 1.2 μm. As is from the later described Example, the results obtained are in the electrostatic adhesion the better, the more a sample is supercalendered to its smoothness to improve. Taking into account the above is a connection between the surface roughness and electrostatic adhesion derived, and suppressing a surface roughness is used as an indicator of the improvement of electrostatic adhesion.

It It should be noted that during the insert paper for glass-like Flat materials above in detail in the present invention, in the manufacture of the insert paper embossing under Use of the formative Roller can be omitted when fusing the spun fibers, and only pressing by the flat roller are performed can. Furthermore, when producing the insertion paper, comprising the nonwoven sheet, pressing by the flat roll and supercalendering as appropriate in the process consideration production equipment, production costs, etc. she are not limited to the above method.

EXAMPLE

The Inventors, as described above, used a nonwoven sheet, produced from cellulose without using a binder than that inserting paper for glass-like Sheet materials of the present invention. They created a nonwoven sheet, prepared by the viscose method as described in detail above (made by Futamura Kagaku Kogyo K.K., Taiko TCF) as the inserting paper for glass-like Sheet materials of the example of the invention. The nonwoven sheet of the example was pressed by a flat roller at the time of embossing, as a treatment for dust prevention.

Of Further, they made a comparative assessment of the insert paper Example of the invention by using insertion paper as Comparative Examples, as an insertion paper for glass materials for flat panel display substrates has been used. For the insert paper In Comparative Examples, they used insertion paper comprising acid Paper made by porridge through the ordinary Process (manufactured by N, NDP) as a comparative example 1, insert paper, comprising neutral paper (manufactured by N, NDP) as a comparative example 2, and insert paper made from recycled paper (manufactured by T, ATP) as a comparative example Third

measurement of solubility in hot water

The inserting paper Example of the invention and Comparative Examples 1 to 3 were based on the above "TAPPI T207 om-81, Water Solubility of Wood and Pulp, 6.2. Hot Water Solubility. "In particular, a 5 g sample from the insert paper each of the example of the invention and comparative examples 1 taken from 3, 250 g of distilled water were added, and the mixture was boiled continuously for 30 minutes. The extract was filtered, 250 g of distilled water was repeatedly added and boiled was for Continued for 30 minutes. This process was repeated three times, and the extracts of the three times were combined.

Of the Combined extract was concentrated and placed in an evaporator dried, then weighed. The weight ratio of the dried solid The sample was considered to be soluble in hot water Substances (wt .-%) assumed. The results are shown in Table 2.

Table 2

As from the results of Table 2, uses the insert paper for glass-like flat materials Example of the invention no binder at the time of molding of the slurry to paper as compared to the insert paper of Comparative Examples 1 to 3, thus the proportion of soluble in hot water Substances significantly lower. It can be deduced that this effective for preventing paper stains on the glass surface.

rating the effect on the glass surface

The inserting paper Example of the invention and Comparative Examples 1 to 3 was cut into strips, arranged in parallel and between two pieces of laminated glass for a TFT-LCD module is clamped. Furthermore, the glass was sandwiched placed between styrofoam, so applied a uniform pressure and the assembly was secured by rubber bands. The assembly of the laminated glass and the insert paper was for maximum 318 hours at a temperature of 60 ° C and a relative humidity exposed by 95%.

steam was applied to the laminated glass surface of the assembly of the laminated glass and the insertion document, until it was fogged, then a fine porous urethane sponge was used to the insert paper rub in a firm manner, so that a uniform pressure at the arrested surface is applied. The surface of the laminated glass was dried, after which it was repeatedly steamed applied and the degree of peeling the paper stains on the surface, where the insert paper was assessed visually in four stages. In this Rating was the insert paper, the best wiped paper stains from the arrested surface leaves, rated as "1" while insert paper, the worst wiped paper stain leaves the stuck surface rated "4". The values of the rating were for each elapsed time adds up, and a total rating four steps were made. To correctly evaluate the paper stains, was confirmed, that no surface deterioration at the exposed parts of the laminated glass, where no insertion paper was held. Table 3 shows the lapse of the Exposure time and pollution on the surface of the Layer glass.

Table 3

As from Table 3, it can be said that the insert paper Example of the invention good properties and a stable quality compared to the insert paper Comparative Examples.

Based On these results, it is suggested that a clear relationship between the proportion of in hot Water soluble Substances and the contamination on the surface of the laminated glass, in particular, that the insertion paper of the example of the present invention, i. a nonwoven sheet, produced using cellulose without using a binder, suitable as insert paper for glass-like Flat materials at the time of transport or storage of glass substrates, where a high degree of purity is required is.

manufacturing of the nonwoven sheet

Convinced of the suitability of the nonwoven sheet according to the above findings, the inventors made three types of nonwoven sheets differing in basis weight (g / m ² ) and surface roughness (μm) (made by Futamura Kagaku Kogyo KK, Taiko TCF Series) obtained by the viscose method as described in detail above. The three types of nonwoven sheet are shown as Sample 1-1, Sample 1-2 and Sample 1-3 as follows. It should be noted that only the nonwoven sheet of Sample 1-3 was pressed by a flat roll at the time of embossing.

Of Further, the inventors supercalendered the nonwoven sheet of Sample 1-1, Sample 1-2 and Sample 1-3 to improve the smoothness of the surfaces of the Nonwoven sheets to control. The following is the nonwoven sheet obtained by Supercalendering of Sample 1-1 is referred to as Sample 2-1, the nonwoven sheet, obtained by supercalendering Sample 1-2 is referred to as Sample 2-2, and the nonwoven sheet obtained by supercalendering from Sample 1-3 is referred to as Sample 2-3. The conditions of the Supercalendering was 14 stages, 13 columns, a linear pressure of 1960 N / cm, a temperature of 80 ° C and a processing speed of 60 m / min.

measurement of surface roughness

The surface roughness the nonwoven sheets the samples were analyzed using a KES-FB-4S surface tester, manufactured by KES Co. The measurement conditions were one stationary Load of 98 mN, a stress of 196 mN / cm, a tester contact length of 5 mm, a pulling speed of 0.1 cm / sec. and a train distance of 2 cm. At the time of measuring the samples was taken a measurement five times carried out, each vertical and horizontal. The mean vertical and the Mean horizontal were calculated, and the larger value was called the surface roughness every sample used.

measurement of electrostatic adhesion

In a room maintained at a temperature of 20 ° C and a relative humidity of 65%, were nonwoven sheets the samples to the size of A4 (about 210 mm × 297 mm), and were cut to a TFT-LCD module laminated glass, cut to the same A4 size, laid. From the above nonwoven sheets became an electrostatic charging system (Electrostatic Eliminator JPK-3, manufactured by Kasuga Denki Inc.) used a static electricity for charging from 20 kV to give. In this case, the opening became the charging electrode of the electrostatic charging system at a position of 5 cm right over the nonwoven sheets the samples retained while charging the nonwoven sheets as a whole.

Of the sufficiently charged assembly of the laminated glass and the nonwoven sheets of Samples became complete turned from top to bottom and the number until the nonwoven sheets of the Samples completely peeled and falling off the laminated glass was calculated. Indeed the time was measured only up to 20 seconds.

The physical properties and measurement results of nonwoven sheets of Sample 1-1, Sample 1-2, Sample 1-3, Sample 2-1, Sample 2-2 and Sample 2-3 and the above Comparative Example 2 (neutral paper) are shown in Table 4.

Table 4

As can be seen from Table 4, as compared with Sample 1-1, Sample 1-2 and Sample 1-3, the supercalendered Sample 2-1, Sample 2-2 and Sample 2-3 have all the values of lowered surface roughness. It is concluded that the electrostatic adhesion of the samples (time of tacked state) also improved greatly. Therefore, it can be said that the smoothness of the surface of the nonwoven sheet is effective in improving the electrostatic adhesion. Furthermore, by comparison egg For Example 2-1, Sample 2-2 and Sample 2-3 with Comparative Example 2, an electrostatic adhesion equal to that of the conventional insert paper (Comparative Example 2, neutral paper) was found. Therefore, the inventors proved that adhesion to glass-like sheets using static electricity becomes possible when using supercalendered nonwoven sheet, and the convenience of the work of inserting the insert paper into the glass-like sheets is improved.

measurement of Generation of dust

In A Class 10000 clean air room was a single polyvinylchloride hood with dimensions of vertical 700 mm, horizontal 500 mm and depth 500 mm assembled, which can only be opened on one side. A hole was created in the middle of the roof of this simple hood. The suction an air particle counter (The Portable, manufactured by HIAC / ROICO) was about 10 inches inside the simple hood hung.

Nonwoven sheets of Sample 1-1, Sample 1-2, Sample 1-3, Sample 2-1, Sample 2-2 and Sample 2-3, previously cut to A4 size (about 210 mm × 297 mm), were from their original Dimensions folded to 1/8 size. Next The above simple hood was opened by about 100 mm, and the folded nonwoven sheets of the Samples were cut eight times in total, each using of cutting scissors, at a speed of 5 seconds per time, at about the center of the simple hood.

Under the particles resulting from the above cutting of the samples flew into the clean air space, were in particular the particles of at least 0.3 μm in size the above mentioned Air particle counter measured. The results of the count are shown in Table 5. It should be noted that counting the Particles were found to be the number of particles per unit cubic feet. For comparison Values, expressed in units of cubic meters, are also given.

Table 5

As from Table 5, as compared with Sample 1-1, Sample 1-2 and Sample 1-3 had supercalendered sample 2-1, sample 2-2 and Sample 2-3 all a particle count that reduces by about half was. Therefore, it can be seen that supercalendering as Treatment for avoiding the generation of nonwoven sheet dust is.

When Result can be the application of insert paper in the past limited was on the use for the "glass layer" to later with a thin one Film to be coated to form a glass substrate on the Transport or storage of "glass substrates", the display manufacturers supplied will be extended. Therefore, even during transport or the Storage of glass substrates, etc., can reduce the amount of transportation and the amount of storage per time can be improved without resorting to packaging spacers.

While the Invention with reference to a particular embodiment, chosen in the Intention of illustration, described, should be understood be made that numerous modifications by a person skilled in the art can be without departing from the basic concept and scope of the invention.

inserting paper for clean glasslike Flat materials, the cost of transportation and storage reduced, without relying on packaging spacers resorting, which prevents paper stains and ensures electrostatic adhesion, comprising a nonwoven sheet made of regenerated cellulose, obtained by the viscose method, copper ammonium method, or another cellulose regenerating process, in particular one, that in proportion of in hot Water soluble Fabrics (in hot Water soluble Ingredients) to less than 0.1% by weight per unit of nonwoven sheet is lowered, wherein the nonwoven sheet is generated so that the regenerated Cellulose fibers over melted parts are fused, without the use of a binder, and the surface The nonwoven sheet is used to prevent dust by, for example, pressing through a flat roller, suction through an aspiration system, etc. The resulting nonwoven sheet may be supercalendered.

Claims (4)

inserting paper for glassy Sheet materials comprising a cellulose-made nonwoven sheet, wherein the nonwoven sheet produces without the use of a binder is, and wherein a portion of soluble in hot water Substances measured based on "TAPPI T207 om-81, Water solubility of Wood and Pulp, 6.2. Hot water solubility ", in the nonwoven sheet less than 0.1 Weight percent is. insertion Paper for glassy The sheet materials of claim 1, wherein the nonwoven sheet passes through a flat roller is pressed. inserting paper for glassy Sheet materials according to one of claims 1 or 2, wherein the nonwoven sheet is supercalendered. inserting paper for glassy Sheet materials according to any one of claims 1 to 3, wherein a surface roughness of the nonwoven sheet not more than 1.5 μm as measured by a KES-FB-4S Surface tester, is.