JP2007262118A - Biodegradable polyester resin composition for light scattering sheet and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a biodegradable resin composition for a light scattering layer of a light scattering sheet using an organic solvent-soluble biodegradable polyester resin, in more detail, a biodegradable polyester resin composition for a light scattering sheet, which is a resin composition comprising light-focusing beads dispersed by using a polyester resin (A), keeps transparency, has excellent adhesivity and heat resistance and is useful for improvement in contrast of especially a liquid crystal display, etc. <P>SOLUTION: In the polyester resin (A) that is produced by copolymerizing lactic acid and a 2-30C dicarboxylic acid as acid components with a 2-30C glycol as a glycol component, the biodegradable polyester resin composition for a light scattering sheet comprises light-focusing beads dispersed in the copolyester (A) having the ratio of lactic acid of 40-98 mol%, a glass transition temperature of ≤70°C, a reduced viscosity of ≥0.20 dl/g and an acid value of ≤300 equivalents/10<SP>6</SP>g. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a biodegradable polyester resin composition for a light-scattering layer of a light-scattering sheet. More specifically, the condensing beads are dispersed to maintain transparency, and have excellent adhesion and heat resistance. The present invention relates to a biodegradable polyester resin composition for a light scattering sheet, which is a resin composition possessed together, and is particularly useful for improving the contrast of displays such as liquid crystals.

Liquid crystal displays are used as various display elements such as clocks, calculators, TVs, word processors, and personal computers due to their features such as low voltage drive, low power consumption, and thin display. Yes. A number of technological developments have been carried out as supporting technologies, such as cell substrates, spacers, light sources, drive technologies, liquid crystal materials, display methods, sealants, color filters, electrode technologies, alignment films, etc. It becomes an excellent liquid crystal display element only when is completed in parallel. However, many improvements and problems still remain.

In order to improve the contrast of a liquid crystal display, it is necessary to improve the light intensity of the Baclite light source, which is a light source, but at the same time there is a problem that the temperature rises during use at the same time as power consumption improves, and there are restrictions on use is there. For this reason, the transparency of the upper polarizing plate, the transparency of the glass substrate, the transparency of the ITO (indium tin oxide) film, the alignment film, the liquid crystal material, the transparency of the spacer beads, the color filter Contrast of liquid crystal display is improved by improving various technologies such as transparency improvement, reflection plate reflection improvement, light guide plate transparency improvement, prism sheet condensing rate improvement, brightness improvement by increasing the number of prism sheets. Is insufficient.

In addition, when polylactic acid is used in consideration of environmental problems (Patent Document 7), there is a problem in long-term water resistance and weather resistance because hydrolyzability is too fast. In addition, polylactic acid is poorly soluble, and particularly difficult to use as a biodegradable polyester resin composition for light scattering sheets because it does not dissolve in general-purpose solvents such as toluene, 2-butanone, and cyclohexanone.

Japanese Patent Laid-Open No. 10-287735 Japanese Patent Laid-Open No. 2001-40079 JP 2001-114882 A JP 2003-252966 A JP-A-8-73582 Japanese Patent Laid-Open No. 10-287735 JP-A-2-238564

An object of the present invention relates to a biodegradable polyester resin composition for a light-scattering layer of a light-scattering sheet using a biodegradable polyester resin soluble in an organic solvent, and condensing beads using the polyester resin (A). A biodegradable polyester resin composition for light scattering sheets that is particularly useful for improving the contrast of liquid crystal displays, etc. It is to provide.

In view of these problems, the present inventors maintain a light intensity necessary for improving the contrast of a liquid crystal display, and are suitable for a light scattering sheet used for a liquid crystal display or the like that can obtain adhesion and heat resistance with a base material sheet. As a result of intensive studies on the resin composition, the present invention has been completed.

That is, the present invention
(1) In the polyester resin (A) in which lactic acid and a dicarboxylic acid having 2 to 30 carbon atoms are copolymerized as an acidic component and a glycol having 2 to 30 carbon atoms is copolymerized as a glycol component, the proportion of lactic acid is 40 to 98 mol% The condensing beads are dispersed in the polyester resin (A) having a glass transition temperature of 70 ° C. or less, a reduced viscosity of 0.20 dl / g or more, and an acid value of 300 equivalents / 10 ⁶ g or less. A biodegradable polyester resin composition for a light scattering sheet.
(2) The polyester resin (A) and the curing agent (B) capable of reacting with the polyester resin (A) are blended in a ratio of (A) / (B) = 95 / 5-60 / 40 (weight ratio). The biodegradable polyester resin composition for light scattering sheets according to (1), wherein the light collecting beads are dispersed.
(3) The manufacturing method of the resin composition for light scattering sheets in any one of said (1)-(2).
It is.

The liquid crystal display light condensing agent dispersion resin composition of the present invention has excellent transparency, maintains the light intensity necessary for improving the contrast of the liquid crystal display, and also has both adhesion and heat resistance, thereby providing liquid crystal It is possible to meet high required quality in such fields. The polyester resin (A) used in the present invention is a biodegradable polymer, but has excellent coating film properties, particularly water resistance and weather resistance. Even more surprising is the outstanding solvent solubility not available in the prior art, not only for dispersing liquid crystal display concentrators, but also when used alone or in combination with known curing agents. Remarkably effective in places where it is necessary to prevent the light from the illuminating light from being reflected on the display part of transmissive liquid crystal panels such as panel meters and clocks, and screens such as word processors and computers, making it difficult to see the display part and screen. It is an excellent one that can be used in a portion where various kinds of light are reflected.

Specific examples of the dicarboxylic acids having 2 to 30 carbon atoms that are acid components other than lactic acid in the present invention include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and 2,6-naphthalenedicarboxylic acid, Alicyclic dicarboxylic acids such as 4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, azelaic acid, pimelic acid , Suberic acid, aevatic acid, undecanoic acid, dimer acid, glycolic acid, 2-hydroxyisobutyric acid, 3-hydroxybutyric acid, 16-hydroxyhexadecanoic acid, 2-hydroxy-2-methylbutyric acid, 12-hydroxystearic acid, apple Aliphatic dicar such as acid, citric acid, gluconic acid Such as phosphate and the like. Of these, aliphatic dicarboxylic acids are preferred from the standpoint of decomposition product safety. Also included are intramolecular esters of hydroxy acids such as caprolactone, cyclic dimers of α-hydroxy acids such as glycolide, lactide, and lactide.
In addition, polyvalent carboxylic acids such as trimellitic anhydride and pyromellitic anhydride may be used in combination as long as the effects of the present invention are not impaired.

Specific examples of the glycol component having 2 to 30 carbon atoms in the present invention include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, , 5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propane Diol, 2-butyl-2-ethyl-1,3-propanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2 -Cyclohexanedimethanol and the like. Among these, ethylene glycol, propylene glycol, 1,4-butanediol, and 2,3-butanediol are preferable from the viewpoint of decomposition product safety. Moreover, you may use together polyhydric polyols, such as a trimethylol ethane, a trimethylol propane, glycerol, and a pentaerythritol, in the range which does not impair the effect of this invention.

Further, metal salts such as 5-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5 [4-sulfophenoxy] isophthalic acid, 2-sulfo-1,4-butanediol, 2,5-dimethyl You may use dicarboxylic acid or glycol containing sulfonic-acid metal bases, such as metal salts, such as -3-sulfo-2,5-hexanediol, in 15 mol% or less of a total acid or a total glycol component.

In the polyester resin (A) of the present invention, the proportion of lactic acid is 40 to 98 mol%. Here, the proportion of lactic acid is the proportion when the total of the acid component and glycol component constituting the polyester resin (A) is 100 mol%. Further, when the proportion of lactic acid is less than 40 mol%, biodegradability tends to deteriorate, and when it exceeds 98%, the solubility in general-purpose solvents tends to decrease.

Further, after polymerization of the polyester resin in the polyester resin (A) of the present invention, trimellitic anhydride, phthalic anhydride, pyromellitic anhydride, succinic anhydride, 1,8-naphthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride An acid value may be imparted by post-adding an acid or the like. By imparting an acid value, solubility can be further improved. The acid value of the polyester resin (A) of the present invention is 300 equivalents / 10 ⁶ g or less, preferably 200 equivalents / 10 ⁶ g or less. If the acid value exceeds 300 equivalents / 10 ⁶ g, good water resistance cannot be obtained.

The polyester resin (A) of the present invention has a glass transition temperature of 70 ° C. or lower, preferably 60 ° C. or lower. When the glass transition temperature exceeds 70 ° C., good adhesion cannot be obtained.

The reduced viscosity of the polyester resin (A) of the present invention is 0.20 dl / g or more, preferably 0.30 dl / g or more, more preferably 0.40 dl / g or more, most preferably 0.45 dl / g or more. is there. When the reduced viscosity is less than 0.20 dl / g, good coating properties cannot be obtained.

As a method for synthesizing the polyester resin (A) of the present invention, a known method is used. Preferably, a method in which the polyester resin (A) is charged all at once and dehydrated and esterified and polycondensed, and a carboxylic acid of lactic acid is esterified with another glycol. Then, after adding other acid, esterification and polycondensation are carried out, and after esterification with other acid or glycol, lactide is added and ring-opening reaction is carried out.

The biodegradable polyester resin composition of the present invention can be used by blending a curing agent (B) capable of reacting with the polyester resin (A).

Examples of the curing agent (B) that can react with the polyester resin (A) include alkyl etherified amino formaldehyde resins, epoxy compounds, and isocyanate compounds.

The alkyl etherified aminoformaldehyde resin is, for example, formaldehyde or paraformaldehyde alkylated with an alcohol having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, urea, N, N -Condensation products with ethylene urea, dicyandiamide, aminotriazine, etc., and methoxylated methylol-N, N-ethyleneurea, methoxylated methylol dicyandiamide, methoxylated methylol benzoguanamine, butoxylated methylol benzoguanamine, methoxylated methylol melamine, butoxylated Examples include methylol melamine, methoxylated / butoxylated mixed methylol melamine, and butoxylated methylol benzoguanamine. Et Preferred are methoxy methylol melamine, butoxy methylol melamine or methoxylated / butoxylated mixed melamine, may be used alone or in combination.

Examples of epoxy compounds include diglycidyl ether of bisphenol A and oligomers thereof, diglycidyl ether of hydrogenated bisphenol A and oligomers thereof, orthophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, and p-oxybenzoic acid diglyceride. Glycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1 , 4-Butanediol glycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene group Diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4-diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether , Pentaerythritol tetraglycidyl ether, triglycidyl ether of a glycerol alcohol oxide adduct, and the like.

Furthermore, the isocyanate compound includes aromatic and aliphatic diisocyanates, and trivalent or higher polyisocyanates, which may be either low molecular compounds or high molecular compounds. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate or trimers of these isocyanate compounds, and excess of these isocyanate compounds And low molecular active hydrogen compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine or various polyester polyols, polyether polyols, polyamides Reacts with polymer active hydrogen compounds Terminal isocyanate group-containing compounds obtained Te are exemplified.

The isocyanate compound may be a blocked isocyanate. Examples of the isocyanate blocking agent include phenols such as phenol, thiophenol, methylthiophenol, ethylthiophenol, cresol, xylenol, resorcinol, nitrophenol, chlorophenol, oximes such as acetoxime, methylethyl ketoxime, cyclohexanone oxime, methanol, Alcohols such as ethanol, propanol and butanol, halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol, tertiary alcohols such as t-butanol and t-pentanol, and ε-caprolactam , Δ-valerolactam, γ-butyrolactam, β-propylolactam, and other lactams, and other aromatic amines, imides, acetylacetone Acetoacetic ester, active methylene compounds such as malonic acid ethyl ester, mercaptans, imines, ureas, and also such as diaryl compounds sodium bisulfite. The blocked isocyanate is obtained by subjecting the above isocyanate compound and an isocyanate blocking agent to an addition reaction by a conventionally known method.

These crosslinking agents can be used in combination with a known curing agent or accelerator selected according to the type.

The resin composition for paints of the present invention is suitable for coating biodegradable plastics. In this case, the baking temperature is the size, thickness of the biodegradable plastics, the ability of the baking furnace, the curability of the paints, etc. Is arbitrarily selected. For the production of the coating composition, a mixer such as a roll kneader, a ball mill or a blender is used. When painting, roller coating, roll coater, spray coating, electrostatic coating, etc. are selected as appropriate.

The coating composition of the present invention may contain additives such as pigments such as titanium oxide, glass fibers, silica, and wax depending on the purpose and application.

As the catalyst for the polycondensation reaction of the present invention, a known catalyst can be used.
The polycondensation catalyst is mainly composed of a compound containing at least one element selected from the group consisting of Ge, Ti, Al, Mn, Fe, Co, Zn, Nb, Mo, Cd, In, Sn, Ta, Pb, and Sb. It is preferable to use at least one selected. These compounds are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries and the like.

Examples of the Ge compound include amorphous germanium dioxide, crystalline germanium dioxide powder or ethylene glycol slurry, a solution obtained by heating and dissolving crystalline germanium dioxide in water, or a solution obtained by adding ethylene glycol to this and heat treatment. In particular, in order to obtain the polyester used in the present invention, it is preferable to use a solution in which germanium dioxide is dissolved by heating in water, or a solution in which ethylene glycol is added and heated. In addition, compounds such as germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, and germanium phosphite can also be used.

Specific examples of the Ti compound include tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate, tetra-n-butyl titanate and partial hydrolysates thereof, titanium acetate, titanyl oxalate. , Titanyl ammonium oxalate, titanyl sodium oxalate, potassium titanyl oxalate, calcium titanyl oxalate, titanium strontium oxalate, etc. Titanium fluoride, potassium hexafluorotitanate, ammonium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, titanium acetylacetonate, titanium and silicon or zirconium A composite oxide, a reaction product of titanium alkoxide and a phosphorus compound, a reaction product obtained by reacting a phosphorus compound with a reaction product of titanium alkoxide and an aromatic polyvalent carboxylic acid or an anhydride thereof, and the like. Can be mentioned. The Ti compound is added so that the remaining amount of Ti in the produced polymer is in the range of 0.1 to 50 ppm.

Specific examples of the aluminum compound include aluminum formate, aluminum acetate, basic aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate, aluminum benzoate, aluminum trichloroacetate, and aluminum lactate. , Carboxylates such as aluminum citrate, aluminum salicylate, inorganic acid salts such as aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum carbonate, aluminum phosphate, aluminum phosphonate, aluminum methoxide, aluminum ethoxide, aluminum Aluminum such as n-propoxide, aluminum iso-propoxide, aluminum n-butoxide, aluminum t-butoxide Aluminum alkoxide, aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, aluminum ethyl acetoacetate diiso-propoxide, organoaluminum compounds such as trimethylaluminum, triethylaluminum and partial hydrolysates thereof And aluminum oxide. Of these, carboxylates, inorganic acid salts and chelate compounds are preferred, and among these, aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferred.

As the usage-amount of the aluminum compound of this invention, 0.001-1.0 mol% is preferable with respect to the number-of-moles of all the structural units of carboxylic acid components, such as dicarboxylic acid and polyhydric carboxylic acid of polyester obtained, Furthermore, Preferably, it is 0.005-0.5 mol%. Thus, the amount of the aluminum component to be added is required to be wide because the catalytic activity varies greatly depending on the type and combination of polyvalent carboxylic acid and diol used, and the polymerization method. This shows the same tendency with other polymerization catalysts. Particularly when the polymerization is not carried out under reduced pressure, the amount of the polymerization catalyst needs to be greatly increased. Since the polymerization catalyst of the present invention exhibits sufficient catalytic activity, as a result, the resulting polyester has excellent thermal stability, thermal oxidation stability, and hydrolysis resistance, and the generation and coloring of foreign matters due to aluminum are suppressed. .

Below, the specific example of the preparation method of the same solution using basic aluminum acetate as an aluminum compound is shown.
Examples of preparation of an aqueous solution of basic aluminum acetate are as follows. That is, water is added to basic aluminum acetate and sufficiently diffused at room temperature, and then dissolved at room temperature to 100 ° C. to prepare an aqueous solution. In this case, the temperature is preferably low, and the heating is preferably short. The concentration of the aqueous solution is preferably 10 to 30 g / l, particularly preferably 15 to 20 g / l.

Furthermore, in order to suppress the heat shock at the time of catalyst addition, it is a preferable aspect that the basic aluminum acetate aqueous solution is the same ethylene glycol solution. That is, ethylene glycol is added to the above aqueous solution. The amount of ethylene glycol added is preferably 0.5 to 5 times the volume ratio of the aqueous solution. More preferably, the amount is 0.8 to 2 times. After stirring the solution to obtain a uniform water / ethylene glycol mixed solution, the solution is heated and water is distilled off to obtain an ethylene glycol solution. The temperature is preferably 70 ° C. or higher, and preferably 130 ° C. or lower. More preferably, the water is distilled off by heating and stirring at 80 to 120 ° C. More preferably, heating is performed under reduced pressure and / or an inert gas atmosphere such as nitrogen or argon, and water is distilled off to prepare a catalyst solution. The above ethylene glycol is an example, and other alkylene glycols can be used in the same manner. In particular, when alkylene glycol having a high melting point and solid at room temperature is used, it can be used as an aluminum compound / alkylene glycol solid solution.

The basic aluminum acetate described above is solubilized in a solvent such as water or alkylene glycol, in particular, water and / or solubilized in alkylene glycol is used from the viewpoint of catalytic activity and reduction of foreign matter in the resulting copolymerized polyester. Is also preferable.

On the other hand, in the present invention, it is preferable that at least one selected from a small amount of an alkali metal, an alkaline earth metal, and the compound in addition to aluminum or a compound thereof coexists as the second metal-containing component. The coexistence of such a second metal-containing component in the catalyst system increases the catalytic activity, and thus a catalyst component having a higher reaction rate can be obtained, which is effective in improving productivity.

When adding an alkali metal, an alkaline earth metal and a compound thereof, the amount M (mol%) used is 1 × 10 ⁻⁶ or more and 0.1 or more relative to the number of moles of all polycarboxylic acid units constituting the polyester. It is preferably less than mol%, more preferably 5 × 10 ^{−6 to} 0.05 mol%, still more preferably 1 × 10 ^{−5 to} 0.03 mol%, and particularly preferably 1 × 10 10. ^{-5 to} 0.01 mol%. Since the addition amount of alkali metal and alkaline earth metal is small, it is possible to increase the reaction rate without causing problems such as deterioration of thermal stability, generation of foreign substances, coloring, deterioration of hydrolysis resistance, etc. is there. When the amount M of the alkali metal, alkaline earth metal, or compound thereof is 0.1 mol% or more, the thermal stability decreases, the generation of foreign matter and coloring, and the hydrolysis resistance become problems in product processing. A case occurs. When M is less than 1 × 10 ⁻⁶ , the effect is not clear even when added.

In the present invention, the alkali metal or alkaline earth metal constituting the second metal-containing component preferably used in addition to aluminum or a compound thereof includes Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr. , Ba is preferable, and among these, at least one selected from Li, Na, Mg or a compound thereof is more preferable. Examples of the alkali metal and alkaline earth metal compounds include saturated aliphatic carboxylates such as formic acid, acetic acid, propionic acid, butyric acid, and succinic acid, and unsaturated aliphatic carboxylates such as acrylic acid and methacrylic acid. , Aromatic carboxylates such as benzoic acid, halogen-containing carboxylates such as trichloroacetic acid, hydroxycarboxylates such as lactic acid, citric acid and salicylic acid, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen carbonate, phosphorus Inorganic acid salts such as acid hydrogen, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid and bromic acid, and organic sulfonates such as 1-propanesulfonic acid, 1-pentanesulfonic acid and naphthalenesulfonic acid , Organic sulfates such as lauryl sulfate, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butyl Alkoxides such as alkoxy, chelate compounds and the like acetylacetonate, hydrides, oxides, and hydroxides and the like.

Among these alkali metals, alkaline earth metals or their compounds, when using strongly alkaline ones such as hydroxides, these tend to be difficult to dissolve in diols such as ethylene glycol or organic solvents such as alcohols. However, it must be added to the polymerization system in an aqueous solution, which may cause a problem in the polymerization process. Furthermore, when a strongly alkaline material such as a hydroxide is used, the polyester is liable to undergo side reactions such as hydrolysis during the polymerization, and the polymerized polyester tends to be colored, and the hydrolysis resistance also decreases. Tend to. Accordingly, the alkali metal or their compounds or alkaline earth metals or their compounds suitable for the present invention are preferably saturated aliphatic carboxylates, unsaturated aliphatic carboxylates, aromatics of alkali metals or alkaline earth metals. Aromatic carboxylates, halogen-containing carboxylates, hydroxycarboxylates, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen phosphate, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid, bromic acid Selected inorganic acid salts, organic sulfonates, organic sulfates, chelate compounds, and oxides. Among these, from the viewpoint of ease of handling, availability, and the like, it is preferable to use an alkali metal or alkaline earth metal saturated aliphatic carboxylate, particularly acetate.
Moreover, the base material sheet by which metals, such as silver and aluminum, are vapor-deposited to the said base material sheet, and it is reflected by a metal vapor deposition layer and light is spread | diffused uniformly can also be used.

The condensing beads of the present invention are condensing beads made of glass, acrylic resin, urethane resin, vinyl chloride resin, or polycarbonate resin, and the particle diameter of the beads is preferably 1 to 500 μm. Also, it can be used by blending two or more kinds of condensing beads.

In addition, 20-90 weight% is favorable for content of the condensing bead of this invention. If it is less than 20% by weight, light is not diffused uniformly, and if it exceeds 90% by weight, adhesion cannot be obtained.

The coating temperature of the resin composition of the present invention is arbitrarily selected depending on the size and thickness of the substrate, the capability of the baking oven, the curability of the paint, and the like. A mixer such as a roll kneader, a ball mill, or a blender is used for producing the light concentrator dispersant. For coating, roller coating, roll coater, spray coating, electrostatic coating, and the like are appropriately selected. The coating composition of the present invention may contain additives such as silica and wax depending on the purpose and application.

The present invention will be illustrated by the following examples, but the present invention is not limited thereto. In the examples, “parts” means “parts by weight”. In addition, each measurement item in an Example followed the following method.

1. Reduced viscosity (dl / g)
0.10 g of polyester resin was dissolved in 25 cc of a mixed solvent of phenol / tetrachloroethane (weight ratio 6/4) and measured at 30 ° C.

2. It measured with the temperature increase rate of 20 degree-C / min using the glass transition point temperature differential scanning calorimeter (DSC). As a sample, 5 mg of a sample was placed in an aluminum press-lid container and crimped.

3. Acid value (equivalent / 10 ⁶ g)
A 0.2 g sample was precisely weighed and dissolved in 20 ml of chloroform. Subsequently, it titrated with 0.01N potassium hydroxide (ethanol solution). Phenolphthalein was used as an indicator.

4). The polyester resin (A) (1) transparency, (2) degree of coloration (1) and (2) were visually determined while the polyester resin was in the form of a plate having substantially the same thickness.
(1) Transparency of resin ○: Almost transparent Δ: Slightly turbid ×: Remarkably turbid (2) Degree of resin coloring ○: Almost not colored Δ: Slightly colored ×: Remarkably colored

5). The soluble polyester resin was heated and dissolved in a solvent of 2-butanone (MEK) / toluene = 50 parts / 50 parts, and the appearance was visually determined. Those having good solubility were indicated as ◯, and those having poor solubility as ×.

6). Dispersible polyester resin (A) solution (MEK / toluene = 1/1 volume ratio) 100 solid parts of acrylic beads (particle size 5-40 μm) (Nippon Exlan Co., Ltd. AR-650) 140 solid parts are dispersed and dispersed. The time was fixed and the varnish appearance was visually confirmed. (○: Good, Δ: Slightly poor dispersion, ×: Dispersion poor)

7). A sample plate was embedded in biodegradable soil, and the gloss retention (%) after one year was measured. The lower the gloss retention, the better the biodegradability.

8). The total light transmittance of the light scattering sheet was measured by the method A of JIS K 7105.

9. Gloss (%)
The 60-degree reflectance of the light scattering sheet was measured with a gloss meter.

10. After the adhesive light-scattering sheet was cut into a grid, the tape was peeled off and judged by the number of peels.

11. The heat-resistant light scattering sheet was heat-treated at 100 ° C. for 12 hours, and the appearance was confirmed visually. (○: good, △: slightly discolored, ×: completely discolored)

12 The degree of coloring light scattering sheet was judged visually (○: good, Δ: slightly discolored, ×: completely discolored)

13. The water-resistant light scattering sheet was immersed in boiling water for 3 hours, and the appearance was visually confirmed. (○: Good, △: Blister occurred, ×: Defect)

Synthesis example of resin A of the present invention In a reaction vessel equipped with a stirrer, condenser and thermometer, 75 parts of lactic acid, 20 parts of isophthalic acid, 50 parts of 1,4-butanediol, 150 ppm of germanium as a polymerization catalyst (total acid components at the time of charging) ) And nitrogen substitution was performed, and then esterification reaction was performed from 160 ° C. to 250 ° C. over 4 hours. Subsequently, the pressure in the system was gradually reduced, and the pressure was reduced to 5 mmHg over 50 minutes, and further a polycondensation reaction was performed at 260 ° C. for 60 minutes under a vacuum of 0.3 mmHg or less. As a result of composition analysis such as NMR, the obtained polyester resin A had a molar ratio of three components of lactic acid / isophthalic acid / 1,4-butanediol = 70/15/15. When the reduced viscosity was measured, it was 0.33 dl / g, the acid value was 12 equivalents / 10 ⁶ g, and the glass transition temperature was 50 ° C. Table 1 shows.

Synthesis examples (B to E) of the resin of the present invention and synthesis examples (F to J) of the comparative resin were also synthesized with the compositions shown in Tables 1 and 2 by the method according to the above synthesis example. The resin group of the present invention was superior to the comparative resin in terms of transparency and coloring degree, and its performance was expected as a resin composition for dispersing a liquid crystal display condensing agent.

Example 1
Using biodegradable polylactic acid polyester film (100 μm) Ecologe CA (Mitsubishi Resin Co., Ltd.) as a base material, acrylic resin is added to 100 parts of polyester resin (A) solution (MEK / toluene = 1/1 volume ratio) MB (particle size 5 to 40 μm) (Nippon Exlan Co., Ltd. AR-650) 140 solid part is dispersed, and a coating film of 15 to 20 μm (thickness not including beads) is formed on the base sheet. (Comma) Coating and drying were performed using a roll method to prepare a light scattering sheet. The obtained results are shown in Table 3.

(Examples 2 to 6) and (Comparative Examples 1 to 6)
Hereafter, the composition of Examples 2-6 and Comparative Examples 1-6 was created by the composition shown in Table 3 and Table 4 like Example 1, and the light-scattering sheet was created. Tables 3 and 4 show the test results obtained for Examples 1 to 6 and Comparative Examples 1 to 6. As is clear from the results in Tables 3 and 4, the light scattering sheets obtained according to Examples 1 to 6 have good light transmittance, and also have excellent adhesion, heat resistance, dispersibility, and water resistance. Was. Examples 1-6 satisfy the total light reflectivity, adhesion, heat resistance, gloss, dispersibility and water resistance, while in Comparative Examples 1-6, total light reflectivity, adhesion, heat resistance, A product satisfying all of gloss, dispersibility and water resistance was not obtained.

The polyester resin (A) used in the present invention is not only for dispersing a liquid crystal display light condensing agent, but can be used alone or in combination with a curing agent (B) to transmit a transmissive liquid crystal such as a digital panel meter of a car or a watch. It is an excellent one that has a remarkable effect in places where it is necessary to prevent the light from the illuminating light from being reflected on the display part of the panel, word processor, computer, etc., and making the display part and screen difficult to see. Can be used on the part where the light is reflected.

Claims (3)

In the polyester resin (A) in which lactic acid and a dicarboxylic acid having 2 to 30 carbon atoms are copolymerized as an acidic component, and a glycol having 2 to 30 carbon atoms as a glycol component, the proportion of lactic acid is 40 to 98 mol%, glass transition Light characterized by light-collecting beads dispersed in the polyester resin (A) having a temperature of 70 ° C. or less, a reduced viscosity of 0.20 dl / g or more, and an acid value of 300 equivalents / 10 ⁶ g or less. A biodegradable polyester resin composition for a scattering sheet. The polyester resin (A) and the curing agent (B) capable of reacting with the polyester resin (A) are blended at a ratio of (A) / (B) = 95/5 to 60/40 (weight ratio), and The biodegradable polyester resin composition for a light scattering sheet according to claim 1, wherein condensing beads are dispersed. The manufacturing method of the biodegradable polyester resin composition for light scattering sheets of Claim 1 or 2.