JP2005133282A - Shoji paper improved in ultraviolet blocking function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce Shoji paper (paper for sliding screens of Japanese houses) retaining essential properties and functions thereof, that is, softly permeating natural light into a Japanese living room and forming special living environment in the room, while resisting to deterioration of the living environment by adding actively blocking functions against ultraviolet rays. <P>SOLUTION: This Shoji paper having ≥20 ultraviolet protection factor (UPF) is provided by selecting a substance increasing ultraviolet blocking function (ultraviolet blocking agent) and applying the substance to a paper material having 30-100 g/m<SP>2</SP>unit weight, 40-75% opacity and ≥70% whiteness. As the ultraviolet blocking agent, either one of ultraviolet reflective agents or one of ultraviolet absorbers, or both thereof, are applied. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a shoji paper for blocking ultraviolet rays that blocks ultraviolet rays of transmitted light.

  In this specification, “shoji paper” refers to paper paper to be pasted on window glass, paper material for electric hood, paper script, in addition to the classic paper paper to be pasted on the frame of the shoji. -Paper materials used for offices, stores, and houses in order to obscure the field of view and seek lighting.

  Conventionally, many sheet materials for various uses that have been provided with an ultraviolet blocking function have been proposed. In particular, cloth fiber materials and paper-based materials having an ultraviolet blocking function are described in the following patent documents. .

  For example, Patent Document 1 discloses a thermal recording paper containing a benzoyl-, salicylic acid-based, or cyanoacrylate-based ultraviolet absorber in a thermosensitive coloring layer, and Patent Document 2 discloses wallpaper. The acrylic resin film containing a benzotriazole-based ultraviolet absorber is further provided in Patent Document 3, as a protective film for printed matter, provided with a weather resistant layer containing an ultraviolet absorber on one side of the substrate film, What provided the adhesion layer in the other surface is disclosed.

  Further, Patent Document 4 discloses an opaque polyester fabric using a concentric core-sheath type polyester composite yarn containing titanium oxide in the core and titanium oxide and a benzoxazole-based fluorescent brightening agent in the sheath. Has been proposed.

  Furthermore, Patent Document 5 proposes a textile product that is directly attached to human skin, including a portion containing a first ultraviolet absorber and a dye and a portion containing a second ultraviolet absorber.

Furthermore, Patent Document 6 discloses that the sun protection factor (SPF) of a textile fiber material is improved by a novel compound useful as an ultraviolet absorber (UVA) and a fluorescent whitening agent (UWA). Has been.
JP-A-10-235996 JP-A-2000-226779 JP 2000-319609 A JP-A-8-144151 JP 2003-147617 A JP-A-10-87638

  Conventionally, paper itself is said to be a material that inherently blocks ultraviolet rays, and in shoji paper that uses the translucency that the paper itself has, it is not necessary to positively exclude ultraviolet rays from transmitted light, No special measures were taken for that purpose.

  However, in recent years, the amount of ultraviolet rays contained in sunlight has increased due to global warming, ozone hole destruction, etc., and the human body itself has become more sensitive to ultraviolet rays. It became necessary to prevent.

  The present invention adds a function to actively block ultraviolet rays without losing the original characteristics and functions of shoji paper that creates a unique living environment indoors by softly transmitting natural light to Japanese-style living rooms, offices, and stores. Against the deterioration of the living environment.

Specifically, in shoji paper with a basis weight of 30 to 100 g / m ² , the paper material itself has a unique visible light transmittance, an opacity of about 40% to 75%, and a whiteness of 70% or more. The purpose is to enhance the ultraviolet blocking function of the shoji paper having the characteristics.

  The shoji paper of the present invention is an ultraviolet ray composed of one or both of an ultraviolet reflector and an ultraviolet absorber for enhancing the ultraviolet ray blocking function in a paper material in which papermaking raw materials are selected and blended according to the above characteristics. Applying a blocking agent, the UVF protection factor (UPF Ultraviolet Protection Factor) is 20 or more.

  That is, in the present invention, the ultraviolet blocking function is enhanced by ultraviolet B wave (UV-B) having a wavelength of 290 nm to 320 nm that gives a short-term damage such as sunburn to the skin and long-term damage to the skin. -This means that the transmittance of ultraviolet A wave (UV-A) of 320 nm to 400 nm giving di is reduced, and expressed as a numerical value, the ultraviolet protection rate (UPF) is 20 or more, preferably 25 or more, more preferably 30 That means that

  The UV protection rate (UPF) is determined by, for example, damage to the skin (SPF) as reported in “Happi • July 2003 • www.Happi.com (UV Absorbers For Fabrics)”. ), And according to the US Skin Cancer Foundation, a minimum sun protection rate (SPF) = 15 is recommended to reduce the effects of ultraviolet radiation on the skin. . Therefore, by setting the UV protection factor (UPF) to 20 or more, it is possible to reduce the short-term and long-term damage to the skin due to the ultraviolet rays without causing a problem. The UPF of commercially available shoji paper is about 15 at the maximum.

  Here, the meaning of the UV protection factor (UPF) is explained in relation to the discoloration of the tatami mat when a new tatami mat is laid in a room with a window, for example. When there is no (UPF value is 1), in a room where tatami mats change color in 10 days, when a shoji paper with a commercial paper with a UPF value of 10 is put in the window, the tatami mats will change color in 100 days. Thus, when shoji paper with a UPF value of 20 or more is put in the window, the color will not change unless the tatami mat has passed 200 days or more. Therefore, when using a shoji paper with a UPF value of 20 or more, compared to using a commercially available shoji paper with a UPF value of 10, people living in the room are also protected from ultraviolet rays more than twice.

  The UV protection rate (UPF) in the present invention is not simply converted from the amount of UV transmission (%), but the amount of UV rays reaching the ground and the damage to the skin for each wavelength of UV rays. This is a weighted calculation taking into account the strength.In this specification, the UV protection rate is shown according to the measurement method of Labsphere adopted by the above-mentioned US skin cancer foundation. (UPF) is the first time to evaluate the ultraviolet blocking function of shoji paper.

The Labsphere measurement method adopted by the US Skin Cancer Foundation conforms to AS / NZS 4399: 1996 (Australian / New Zealand Standard "Sun protective clothing-Evaluation and classification"), and uses the following formula: doing.

Therefore, for example, if there is no shielding object, T _λ = 1, so that the numerator and denominator have the same value in the above calculation formula, and UPF = 1.

  According to the data of the Skin Cancer Foundation, the UV protection rate (UPF) and the UV cut rate% are defined as follows.

UPF = 100 / (UV transmittance%)
UV cut rate% = 100-100 / UPF
As can be seen from the above UPF calculation formula, these UV transmittances and cut rates are simply the sum of the UV transmittance and cut rate for each wavelength, the coefficient of the amount of UV rays that reaches the ground for each wavelength, and the skin. Multiply by the coefficient of strength that gives damage. From the above definition, for example, when UPF = 20, the ultraviolet transmittance% is 100 / UPF = 100/20 = 5%, and the ultraviolet cut ratio% is 100−5 = 95%.

Incidentally, the UV transmittance / cut rate commonly used in Japan is simply the sum of the transmittance for each wavelength. For example, according to the unified evaluation method (guideline) of the processing effect of UV-cut material compiled by the Japan Chemical Fiber Association / Dyeing Technology Technical Committee, it is as follows.
“Using a spectrophotometer, the transmittance at a wavelength of 280 to 400 nm is measured, and either the integral value thereof or the integral value of the shielding factor [shielding factor = (1−Ta (transmittance) × 100)]. , Determine the effect of UV protection. "

  In addition, the guidelines of the Japan Chemical Fiber Association include the following descriptions regarding the display terms in the evaluation criteria.

(1) A notation indicating the effect of ultraviolet rays on the human body is not appropriate.
(2) It is appropriate to use appropriate terms as terms that mean to reduce the amount of ultraviolet rays that pass through the textile and hit the skin. The explanation is as follows.
Suitable example: Ultraviolet shielding processing Class A (ultraviolet shielding ratio of 90% or more)
Inappropriate example: UV reflection processing (UV reflection rate 90%)

  Thus, the ultraviolet cut (shielding) rate of the Japan Chemical Fiber Association does not mean the influence of ultraviolet rays on the human body. On the other hand, the UPF (ultraviolet ray protection rate) used in the present invention and the accompanying “ultraviolet ray transmittance” and “ultraviolet ray cut rate” are numerical values for the influence of ultraviolet rays on the human body as described above. Thus, there is an advantage that the user should select a material with a larger value of “UPF” or “UV cut rate”, and applying this to shoji paper is novel.

  In the shoji paper of the present invention, as the paper material, for example, natural bast fibers such as ridges, mitsumata, cancer hide and hemp, cellulose fibers such as wood pulp, cotton linter pulp, rayon, etc. A paper material made from a simple substance or a composite material can be used.

  Cellulose fibers such as pulp, which is the main raw material for paper materials, originally function as ultraviolet absorbers. In particular, it is known that the benzene ring of lignin present as an impurity in cellulose fiber absorbs ultraviolet rays and converts them into heat. Therefore, an unexposed thing with many impurities, that is, a non-white one has a higher ultraviolet absorbing ability.

  Paper materials include glass fiber, micro glass, rock wool, mineral cotton, alumina fiber, alumina silica fiber, mullite fiber, boric acid fiber, quartz fiber, silicate glass fiber, fused silica fiber, potassium titanate. Fibers, zirconia fibers, calcium nitrate fibers, phosphate fibers, polysilicate fibers, carbon fibers, activated carbon fibers, and other inorganic fibers may be blended. Further, vinylon fibers may be blended.

  Furthermore, it is preferable to contain 5 to 100% of hydrophobic heat-shrinkable fibers in order to improve the dimensional stability against changes in humidity and temperature of the paper material sheet main body.

  As the hydrophobic heat-shrinkable fibers, single or composite fibers such as polyethylene, polypropylene, polyester, polyclar, acrylic, vinyl acetate and derivatives thereof are suitable.

  Furthermore, in accordance with the present invention, among the cellulose fibers that are raw materials for papermaking, semi-synthetic fibers such as rayon, the above-mentioned hydrophobic heat-sensitive shrink fibers (synthetic fibers) and vinylon fibers have a function of blocking ultraviolet rays. In order to increase the density, an ultraviolet reflector powder such as a metal oxide can be mixed in a molten resin, extruded from a nozzle to form a fiber, and this fiber material can be used as a raw material for paper. In this case, the blending amount of the ultraviolet reflector powder such as a metal oxide kneaded into the fiber is preferably 0.1 to 10% by weight. If the amount is less than 0.1% by weight, the effect is small, and if it exceeds 10% by weight, it is difficult to produce and is not suitable.

  In the present invention, a fiber material containing the ultraviolet reflector powder, and natural bast fibers such as the above-mentioned ridges, mitsutama, cancer skin and hemp, cellulose such as wood pulp, cotton linter pulp, rayon, etc. A paper material made of a single material or composite material of a glass fiber can also be used. In other words, in the present invention, any blending may be used as long as one or a plurality of the above-mentioned fiber raw materials are selected and paper-made to satisfy the required physical property values as shoji paper. In addition, when an ultraviolet blocker is applied to the fiber material itself of the paper material, since it becomes the main fiber constituting the paper, it is assumed that the whiteness is 70% or more and the opacity is 40% to 75%. In addition, an ultraviolet blocking agent is selected and blended so that the total amount becomes 100% by weight.

In the present invention, a metal oxide powder such as TiO ₂ , ZnO ₂ , Al ₂ O ₃ , SeO ₂ , SiO ₂ , and CaCO ₃ is blended as a filler as the ultraviolet reflector.

  When this UV-reflecting agent is not kneaded into the fiber and applied to the paper material in the paper making stage, impregnation process or coating process, the blending amount is 1 to 20% by weight on the outer side of the paper material. preferable. If it is less than 1% by weight, the ultraviolet ray reflection function cannot be expected due to yield or the like. If the weight exceeds 20%, it becomes difficult to ensure the unique visible light transmittance of the paper material itself and the opacity of about 40% to 75%.

  As the ultraviolet absorber, fluorescent brightener dyes, other low molecular compounds, high molecular compounds, and the like can be used.

  Examples of fluorescent brightener dyes include benzoxazole dyes, stilbene dyes, pyrazoline dyes, coumarin dyes, naphthalimide dyes, and the like. The blending amount of the fluorescent brightener dye is preferably 1% by weight or less as an outer coating with respect to the paper material. If it exceeds 1% by weight, the discoloration becomes intense and is not suitable. As an application method to paper material, there are an internal addition method or a post-processing method in the paper making stage. The internal addition method is less effective than the post-processing method, but the post-processing method increases costs such as investment in processing equipment and a drying process. Therefore, the application method is selected according to the situation.

  In addition, the low molecular weight compounds having an ultraviolet absorbing function include benzotriazine-based, benzotriazole-based, benzophenol-based, salicylic acid-based compounds, benzophenone-based UV absorbers, azomethine-based UV absorbers, and indole-based UV absorbers. Further, triazine-based ultraviolet absorbers can be used. The blending amount of the low molecular weight compound having an ultraviolet absorbing function is preferably 0.1 to 3% by weight. If it is less than 0.1% by weight, an ultraviolet absorbing function cannot be expected. If it exceeds 3% by weight, it is difficult to maintain a whiteness of 70% or more, which is inappropriate. The application method is the same as the application method of the fluorescent brightening agent dye, but unless a fixing agent or an adhesive to the paper material is used, there is a risk that the yield will be deteriorated or it may be detached during use.

  Furthermore, as the polymer compound having an ultraviolet absorbing function, a copolymer obtained by copolymerizing the above-described low molecular compound with a polymer such as polyester, polyamide, polyolefin, or acrylic is used. The blending amount of the polymer compound having an ultraviolet absorbing function is preferably 0.1 to 20% by weight. This is because the low molecular weight compound having the ultraviolet absorbing function is copolymerized with a polymer in order to improve the fixing of the low molecular weight compound to a material. It depends on what percentage it contains. Therefore, it is preferable to mix | blend so that the compounding quantity of the low molecular weight compound which has the ultraviolet-absorbing function contained in a high molecular compound may be 0.1 to 3 weight% with respect to a paper material.

  These ultraviolet absorbers or ultraviolet reflectors may be used alone or in combination of two or more. Moreover, you may use the stilbene disulfonic acid triazine derivative currently disclosed by the said patent document 6 as an ultraviolet blocker provided with the function of both an ultraviolet absorber and an optical brightener. Specifically, 4,4-bis-amino [4-methylamino-6- (4-N-methylformamide) -anilino-1,3,5-triazin-2-yl] -stilbene-2,2 ′ -Disulphonic acid disodium salt. The blending amount of the stilbene disulfonate triazine derivative is preferably 0.2 to 3% by weight as an outer coating with respect to the paper material. If the amount is less than 0.2% by weight, the effect cannot be expected. If the amount exceeds 3% by weight, the effect is saturated and the cost increases.

  As described above, one or two or more paper materials, ultraviolet reflectors, fluorescent brightener dyes, low molecular compounds having an ultraviolet absorption function, and high molecular compounds having an ultraviolet absorption function are selected, and the above blending amount is selected. By blending within the range, the ultraviolet blocking function is enhanced, and the ultraviolet protection rate (UPF) is 20 or more.

  It should be noted that the fluorescent brightener dye absorbs ultraviolet A wave (UV-A), converts the wavelength to a wavelength of 100 nm, and increases the whiteness. Those which mainly absorb ultraviolet B waves (UV-B) are suitable.

When applying these ultraviolet light blocking agents to paper materials, as described above, they are mixed with the paper materials at the raw material blending stage or the paper trough stage, coated onto the paper sheet material, and directly bonded. The emulsion is applied by mixing or copolymerizing with an agent. Further, it is mixed or copolymerized with a pressure-sensitive adhesive such as an acrylate ester, applied to a paper material, provided with a release paper, and finished as a shoji paper for windows. At that time, in order to prevent the adhesive from penetrating into the paper material, there may be provided a barrier layer of thermoplastic resin such as polyethylene, polypropylene, acrylic or polyester. Further, it is possible to adopt a means such as a film obtained by mixing or copolymerizing these ultraviolet light blocking materials with a polyethylene resin, polypropylene resin, acrylic resin, polyester resin, or the like to form a film, and affixing to a paper material. When the shoji paper is formed with a composite layer such as a paper material, an adhesive, or a film, it is sufficient that UPF ≧ 20 in total. At that time, it is needless to say that the shoji paper of the composite layer has the characteristics of rice basis weight = 30 to 100 g / m ² , opacity = 40% to 75%, and whiteness = 70% or more.

  Since the shoji paper of the present invention has been actively enhanced without blocking the original characteristics and functions of shoji paper, it is arranged in houses such as offices, stores and houses. , Can live a safe and comfortable life without UV damage to the human body.

  Embodiments of the present invention will be described below based on examples.

First, as a comparative example, Table 1 shows the raw material of the paper material of a conventional shoji paper and the characteristic values of the obtained shoji paper. Shoji paper was manufactured by a normal paper making method in which raw materials for paper were blended and machined. In addition, in Table 1, in addition to the UV protection rate (UPF) measured according to the above-mentioned Labsphere measurement method, as a reference, the UV transmittance for each wavelength is simply used as is generally done in Japan. -A simple UPF is calculated based on the UV transmittance / cut rate obtained by integrating the cut rates.

  As shown in Table 1, the maximum protection rate (UPF) of conventional shoji paper is 15.

  Hereinafter, examples of the present invention in which an ultraviolet blocking agent is applied to a paper material of type B or type C shown in Table 1 will be described. In each example, the shoji paper was manufactured by the normal paper making method described above. Moreover, the opacity of the shoji paper obtained in each Example was 40% to 75%, and the whiteness was 70% or more. In addition, implementation will not be restrict | limited if it is a combination other than a present Example and a claim is satisfy | filled.

(Example 1)
In this example, a fluorescent brightener dye (referred to as “fluorescent dye” in the examples) was added to a paper material of type C in Table 1 at the stage of blending the raw materials. A stilbene dye was used as the fluorescent dye. Table 2 shows the characteristic values of the obtained shoji paper.

As shown in Table 2, in the paper material of type C {containing 85% by weight of polyester fiber (containing 3% by weight of TiO ₂ powder)}, 0.1% by weight or more of the stilbene-based fluorescent dye is externally applied to the paper material. By the addition, shoji paper having an ultraviolet protection factor (UPF) of 20 or more was obtained.

(Example 2)
In this example, a stilbene fluorescent dye was added to the paper material of type B in Table 1 at the stage of blending the raw materials. Table 3 shows the characteristic values of the resulting shoji paper.

  As shown in Table 3, shoji paper with an ultraviolet protection factor (UPF) of 20 or more by adding 0.4% by weight or more of a stilbene-based fluorescent dye on the paper material of the type B paper. was gotten.

(Example 3)
In this example, a stilbene disulfonic acid triazine derivative (hereinafter referred to as “T derivative”) disclosed in Patent Document 6 was added to the paper material of type B in Table 1 at the stage of raw material blending. Table 4 shows the characteristic values of the resulting shoji paper.

  As shown in Table 4, by adding 0.2% by weight or more of T derivative to the paper material in the type B paper material, shoji paper having an ultraviolet protection factor (UPF) of 20 or more can be obtained. It was.

(Comparative Example 1)
In this comparative example, 0.2% by weight of a stilbene-based fluorescent dye is added to the paper material of type B shown in Table 1 as an outer coating, and after making and drying the paper, an acrylic polymer having an ultraviolet absorbing function. It is impregnated with a compound and a benzotriazole copolymer (ULS-1700 = manufactured by one company). Table 5 shows the characteristic values of the obtained shoji paper.

  As shown in Table 5, the ultraviolet protection rate (UPF) was only 11 even when ULS-1700 having an ultraviolet absorbing function was combined in an amount of 2% by weight. This is because the absorption effect of the fluorescent dye in the ultraviolet A-wave (UV-A) wavelength region and the absorption effect in the ultraviolet A-wave (UV-A) wavelength region of ULS-1700 cancel each other, and the ultraviolet blocking function is achieved. This is thought to be due to lowering.

  Thus, when using an ultraviolet blocking agent in combination, care must be taken. When using an ultraviolet blocking agent that absorbs ultraviolet A wave (UV-A) (mainly a fluorescent brightening agent), the ultraviolet blocking agent used in combination. For example, those which mainly absorb ultraviolet B waves (UV-B) are suitable.

  The shoji paper of the present invention can be used as various paper materials used for blocking the field of view and obtaining light.

Claims (10)

Select a material (ultraviolet blocking agent) that enhances the ultraviolet blocking ability for paper with a rice basis weight of 30-100 g / m ² , opacity of 40% -75%, and whiteness of 70% or more. This is a shoji paper that has been applied to improve the UV blocking function,
This shoji paper is a shoji paper that has an ultraviolet ray blocking rate of 20 or more and has an improved ultraviolet blocking function.   Paper material is a natural bast fiber such as Kozo, Mitsumata, cancer skin, hemp, etc., cellulosic fiber such as wood pulp, cotton linter pulp, rayon, inorganic fiber or synthetic fiber with 0.1 to 0.1 UV reflective powder. 2. The shoji paper having an improved ultraviolet blocking function according to claim 1, wherein the paper material is made of a single material or a composite material of a fiber material blended and melt-spun by 10% by weight.   The shoji paper with enhanced ultraviolet blocking function according to claim 1, wherein the ultraviolet blocking agent comprises one or both of an ultraviolet reflecting agent and an ultraviolet absorbing agent. The ultraviolet reflector is one or more of metal oxides such as TiO ₂ , ZnO ₂ , Al ₂ O ₃ , SeO ₂ , SiO ₂ , CaCO _3, etc. The shoji paper having an enhanced ultraviolet blocking function according to claim 3, wherein is 1 to 20% by weight on the paper material.   The ultraviolet absorber is any one or two or more of a fluorescent brightener dye, a low molecular weight compound and a high molecular weight compound, and a stilbene disulfonic acid triazine derivative having a fluorescent whitening function. Shoji paper with improved UV blocking function.   The fluorescent brightener dye is one or more of benzoxazole dyes, stilbene dyes, pyrazoline dyes, coumarin dyes and naphthalimide dyes. The shoji paper having an improved ultraviolet blocking function according to claim 5, wherein the amount is 1% by weight or less as an outer cover with respect to the paper material.   Low molecular weight compounds having an ultraviolet absorbing function include benzotriazine, benzotriazole, benzophenol, salicylic acid compounds, benzophenone ultraviolet absorbers, azomethine ultraviolet absorbers, indole ultraviolet absorbers and triazine ultraviolet absorbers. 6. The ultraviolet blocking function according to claim 5, wherein the amount of the low molecular compound is 0.1 to 3% by weight as an outer coating with respect to the paper material. Shoji paper.   The high molecular compound having an ultraviolet absorbing function is a high molecular compound obtained by copolymerizing a low molecular compound having an ultraviolet absorbing function with a polymer such as polyester, polyamide, polyolefin, and acrylic, and the low molecular compound constituting this high molecular compound. The shoji paper having an improved ultraviolet blocking function according to claim 5, wherein the blending amount is 0.1 to 3% by weight on the paper material.   6. The shoji paper having an improved ultraviolet blocking function according to claim 5, wherein the blending amount of the stilbene disulfonic acid triazine derivative having a fluorescent whitening function is 0.2 to 3% by weight or less as an outer coating with respect to the paper material. An ultraviolet protection factor (UPF) is obtained by blending an ultraviolet blocking agent into a paper material having a basis weight of 30 to 100 g / m ² , an opacity of 40% to 75%, and a whiteness of 70% or more. A method for producing shoji paper with an ultraviolet blocking function of 20 or more,
A UV blocker composed of either or both of a UV reflector and UV absorber is mixed with the paper material at the raw material mixing stage or the paper basket stage, or applied to the sheet-like paper material, or , A method for producing shoji paper with an improved function of blocking ultraviolet rays applied as a film.