A kind of optical diffusion
Technical field
The utility model relates to a kind of optical thin film, particularly a kind of optical diffusion that is used to produce display panel.
Background technology
Optical diffusion is widely used in liquid crystal indicator, and advertising lamp box, lighting, mobile communication equipment button etc. need on the device of light source so that even illumination to be provided.Fig. 1 is the optical diffusion of known liquid crystal indicator, and this optical diffusion mainly comprises transparency carrier, last diffusion layer and be included in last diffusion particle and antiseized backing layer wherein and be included in wherein antiseized particle.The optical diffusion that traditional employing application pattern is produced mainly relies on the scattering particle of random scatter different size in the overlay that the incident ray that enters in the coating is carried out abundant scattering, so that the direction stochastic distribution of emergent ray, thereby make the inhomogeneous light uniformization of incident, and the flaw of film lower back optical mode set of pieces hidden, simultaneously, because the top of some larger-size particles protrudes in coating surface, formation has the curved surface of certain effect to light, thereby makes this kind optical diffusion sheet have certain light gathering.Diffusion barrier in use frequently is subjected to thermo-contact illumination, aging easily, adhesion between diffusion layer and the transparency carrier dies down, outstanding granule proliferation is loosening because of diffusion layer and the aging efflorescence of himself easily, when being subjected to external force, change form easily, at this moment, diffusion sheet weakens the ray homogenization effect, influences the result of use and the life-span of screen then.
In recent years, fast development along with liquid crystal indicator, with the widespread use of optical diffusion at mobile communication equipment demonstration, laptop computer displays, desktop computer display and large scale liquid crystal TV, performance requirement to optical diffusion in the display device improves day by day, how to improve the fastness of light penetration, diffusion layer and transparency carrier effectively, illumination uniformity becomes the major issue that people need solve.
The utility model content
Technical problem to be solved in the utility model provides a kind of optical diffusion that can effectively improve fastness between the functional layer that applies on light penetration, illumination uniformity and the raising support and support.
For addressing the above problem, the technical scheme that the utility model is taked is:
A kind of optical diffusion, it comprises support, is provided with light diffusion layer on a surface of support, at the another side of support adherent layer is arranged, be respectively equipped with easy adhesive coating between support and the light diffusion layer and between support and the adherent layer, described easy adhesive coating is the amorphism copolyester layer.
A kind of preferred version, the thickness of described easy adhesive coating are 0.5~50 μ m.
A kind of preferred version, the thickness of described easy adhesive coating are 1~30 μ m.
A kind of preferred version, the described light diffusion layer particle of arranging different-grain diameter at random, the biggest size of element of particle is 1.1 to 2 times of described light diffusion layer thickness.
A kind of preferred version, described adherent layer is being arranged the particle of different-grain diameter, and the biggest size of element of particle is 1.1 to 2 times of described adherent layer thickness.
The support of diffusion barrier is any one among glass, PET, PC, PMMA and the PS, in order to obtain the diffusion barrier of high strength, high light line transmitance, low percent thermal shrinkage, takes into account the cost of material, and the preferred PET of the utility model is a support.Described PET mainly is meant the condensation product of dibasic acid and dibasic alcohol, and wherein, dibasic acid can be a straight chain fatty acid, but mainly is aromatic diacid, as terephthalic acid (TPA), to phenylenediacetic Acid, to naphthalenedicarboxylic acid etc.; Dibasic alcohol mainly is that carbon number is 2~4 aliphatic diol, as ethylene glycol, propylene glycol, butylene glycol etc.Except mentioned component, polyester slice can also be the polyester that adds the modification of materials such as a spot of m-phthalic acid, phthalic acid.Being fit to polyester slice of the present utility model is that limiting viscosity is the terephthalic acid (TPA) of 0.5dL/g~0.9dL/g and the condensed polymer ethylene glycol terephthalate of ethylene glycol, and preferred characteristics viscosity is the ethylene glycol terephthalate of 0.6dL/g~0.7dL/g.
The thickness of support is preferably at 38~300 microns, and thickness can not guarantee enough deflections and physical strength during less than 38 microns, when thickness surpasses 300 microns, can cause unnecessary material consumption, and cost improves.
In order to obtain the light penetration height, the optical diffusion that illumination uniformity is high, reduce the loosening or distortion of optical diffusion granule proliferation efflorescence in use aging or that the external force effect causes because of self, the utility model is equipped with easy adhesive coating by two surfaces at support, to increase between light diffusion layer and the support, fastness between adherent layer and the support, reducing optical diffusion frequently is heated because of it, diffusion layer that contacts illumination and cause and the adhesion between support die down, outstanding granule proliferation becomes flexible because of diffusion layer and himself aging produces efflorescence, the distortion of avoiding these particles when being subjected to external force, to occur, improve diffusion barrier to the ray homogenization effect, and then the result of use and the life-span of improving indicator screen.
Easy adhesive coating in the utility model is the amorphism copolyester layer, and described amorphism polyester can be to have added m-phthalic acid, phthalic acid, bisphenol-A or 2, the modified copolyester of compositions such as 6-naphthalenedicarboxylic acid in the polyester molecule chain.Can also be especially ethylene glycol and 1,4 cyclohexane dimethanol and a kind of dicarboxylic acid copolyesters that forms of terephthalic acid (TPA) polymerization especially of aliphatic diol and alicyclic diol, the polyethylene terephthalate of preferred 1,4 cyclohexane dimethanol modification; The thickness of described easy adhesive coating is 0.5~50 μ m, preferred 1~30 μ m.When the thickness of easy adhesive coating is lower than 0.5 μ m, can not guarantee the continuity of the copolyesters distribution on support surface; When the thickness of easy adhesive coating is higher than 50 μ m, can consume the higher copolyesters of excessive cost, increase production cost.
Light diffusion layer of the present utility model is by the diffusion resin, and granule proliferation and mixing diluents are easily applying on the adhesive coating after being prepared into dilution coating, and drying curing forms.The diffusion resin is selected from a kind of or its modified resin in polyacrylic resin class, polyurethanes, the silicone based or polyalcohols; Thinning agent can be one or more the potpourri in toluene, dimethylbenzene, butanone, cyclohexanone, ethanol, isopropyl alcohol, butanone, ethyl acetate, butyl acetate, acetone and the water; Granule proliferation can be that in inorganic particles such as monox, titanium dioxide, aluminium oxide and zinc paste or the organic granulars such as polyacrylic resin, polyacrylonitrile resin and polystyrene resin one or several are mixed and made into; Granule proliferation comprises oarse-grained granule proliferation and short grained granule proliferation, the biggest size of element of oarse-grained granule proliferation is 1.1 to 80 μ m, short grained granule proliferation biggest size of element is 0.1 to 60 μ m, the arrangement at random of bulky grain and granule, the diffusion layer particle is 1.1 to 2 times of described light diffusion layer thickness perpendicular to the biggest size of element of described support, when surpassing this scope, will deterioration light result of use, or make the firm degree of particle die down.The particle by selecting above-mentioned size and the coating thickness condition of setting are adjusted the scattering degree of light, guarantee the firm degree of illumination uniformity and particle.
The thickness of described light diffusion layer is 1~40 micron, when light diffusion layer thickness during less than 1 micron, can not guarantee the degree of uniformity of projection light; When the thickness of light diffusion layer during greater than 40 microns, can stop seeing through of light, reduce transmittance.
Adherent layer of the present utility model contains antiseize resin and antiseized particle.Described antiseize resin is a thermoset resin, is selected from a kind of or its modified resin in polyacrylic resin class, polyurethanes, the silicone based or polyalcohols.Optical diffusion reaches the effect that prevents the vision watermark by the particles of different sizes of arranging in the adherent layer; play the auxiliary effect of adjusting the dispersion effect of light simultaneously; described antiseized particle can be a monox; titanium dioxide; inorganic particle such as aluminium oxide and zinc paste or polyacrylic resin; in the organic granular such as polyacrylonitrile resin and polystyrene resin one or several; the biggest size of element of these particles is greater than 0.1 μ m; be no more than 40 μ m; particle is 1.1 to 2 times of described adherent layer thickness perpendicular to the biggest size of element of described support; when surpassing this scope; will the deterioration anti-adhesion effects, even do not have anti-adhesion effects.The particle by selecting above-mentioned size and the coating thickness condition of setting reach suitable light scatter effect, the best light service efficiency and the firm degree of particle.
Described adherent layer thickness is 0.1~20 micron.When thickness during less than 0.1 micron, can increase the difficulty of coating homogeneity, when thickness during, can stop seeing through of light greater than 20 microns, influence the utilization factor of light, increase raw-material use amount.
The light diffusion barrier that the utility model provides can prepare by following method:
With crystalline polyester resin crystallizing and drying under 150 ℃~180 ℃ conditions, send into corresponding extrusion system then, 250 ℃~300 ℃ fusions; The amorphism conjugated polyester resin can be carried out pre-dried at 50 ℃~80 ℃, send into twin-screw vented extruder or single screw rod vented extruder then, under 240 ℃~270 ℃ temperature, carry out fusion, above-mentioned two kinds of fused materials are extruded by a co-extrusion die head, curtain coating obtains the two-sided support that is provided with easy adhesive coating through the orientation stretching to chilling roll, easily be coated with light diffusion layer and adherent layer respectively on the adhesive coating then, drying obtains optical diffusion.
Compared with prior art, the utility model is provided with easy adhesive coating by two surfaces at support, increased between light diffusion layer and the support, fastness between adherent layer and the support, having reduced optical diffusion frequently is heated because of it, the diffusion layer that contacts illumination and cause, adhesion between adherent layer and support dies down, outstanding particle is because of diffusion layer, adherent layer and himself aging and to produce efflorescence loosening, the distortion of having avoided particle when being subjected to external force, to occur, improve the light penetration and the illumination uniformity of film effectively, improved the result of use and the life-span of indicator screen.
Description of drawings
Fig. 1 is the optical diffusion film structural drawing of prior art;
Fig. 2 is an optical diffusion structural drawing of the present utility model.
Each label list is shown among the figure: 10, support; 11, easy adhesive coating; 31, the particle in the easy adhesive coating; 32, antiseize resin; 21, the bulky grain in the light diffusion layer; 23, granule; 22, diffusion resin.
Embodiment
By following examples the utility model is described.
Embodiment 1
With crystalline polyester resin crystallizing and drying under 150 ℃ of conditions, send into corresponding extrusion system then, 250 ℃ of following fusions; The amorphism conjugated polyester resin can be carried out pre-dried at 80 ℃, send into twin-screw vented extruder or single screw rod vented extruder then, under 240 ℃ temperature, carry out fusion, above-mentioned two kinds of fused materials are extruded by a co-extrusion die head, curtain coating is to chilling roll, obtain the two-sided support 10 that is provided with easy adhesive coating through the orientation stretching, then on easy adhesive coating 11 respectively coating to include biggest size of element be 8 microns bulky grain 21, biggest size of element is 1 micron a granule 23, the light diffusion layer of diffusion resin 22 and to contain biggest size of element be 2 microns particle 31, the adherent layer of antiseize resin 32, dry, obtain optical diffusion as shown in Figure 2, test result sees Table 1.
Embodiment 2
With crystalline polyester resin crystallizing and drying under 170 ℃ of conditions, send into corresponding extrusion system then, 280 ℃ of following fusions; The amorphism conjugated polyester resin can be carried out pre-dried at 50 ℃, send into twin-screw vented extruder or single screw rod vented extruder then, under 260 ℃ temperature, carry out fusion, above-mentioned two kinds of fused materials are extruded by a co-extrusion die head, curtain coating is to chilling roll, obtain the two-sided support 10 that is provided with easy adhesive coating through the orientation stretching, then on easy adhesive coating 11 respectively coating to include biggest size of element be 20 microns bulky grain 21, biggest size of element is 5 microns a granule 23, the light diffusion layer of diffusion resin 22 and to contain biggest size of element be 8 microns particle 31, the adherent layer of antiseize resin 32, dry, obtain optical diffusion as shown in Figure 2, test result sees Table 1.
Embodiment 3
With crystalline polyester resin crystallizing and drying under 180 ℃ of conditions, send into corresponding extrusion system then, 280 ℃ of following fusions; The amorphism conjugated polyester resin can be carried out pre-dried at 70 ℃, send into twin-screw vented extruder or single screw rod vented extruder then, under 270 ℃ temperature, carry out fusion, above-mentioned two kinds of fused materials are extruded by a co-extrusion die head, curtain coating is to chilling roll, obtain the two-sided support 10 that is provided with easy adhesive coating through the orientation stretching, then on easy adhesive coating 11 respectively coating to include biggest size of element be 50 microns bulky grain 21, biggest size of element is 15 microns a granule 23, the light diffusion layer of diffusion resin 22 and to contain biggest size of element be 10 microns particle 31, the adherent layer of antiseize resin 32, dry, obtain optical diffusion as shown in Figure 2, test result sees Table 1.
Embodiment 4
With crystalline polyester resin crystallizing and drying under 180 ℃ of conditions, send into corresponding extrusion system then, 290 ℃ of following fusions; The amorphism conjugated polyester resin can be carried out pre-dried at 70 ℃, send into twin-screw vented extruder or single screw rod vented extruder then, under 260 ℃ temperature, carry out fusion, above-mentioned two kinds of fused materials are extruded by a co-extrusion die head, curtain coating is to chilling roll, obtain the two-sided support 10 that is provided with easy adhesive coating through the orientation stretching, then on easy adhesive coating 11 respectively coating to include biggest size of element be 70 microns bulky grain 21, biggest size of element is 20 microns a granule 23, the light diffusion layer of diffusion resin 22 and to contain biggest size of element be 15 microns particle 31, the adherent layer of antiseize resin 32, dry, obtain optical diffusion as shown in Figure 2, test result sees Table 1.
Embodiment 5
With crystalline polyester resin crystallizing and drying under 170 ℃ of conditions, send into corresponding extrusion system then, 275 ℃ of following fusions; The amorphism conjugated polyester resin can be carried out pre-dried at 80 ℃, send into twin-screw vented extruder or single screw rod vented extruder then, under 250 ℃ temperature, carry out fusion, above-mentioned two kinds of fused materials are extruded by a co-extrusion die head, curtain coating is to chilling roll, obtain the two-sided support 10 that is provided with easy adhesive coating through the orientation stretching, then on easy adhesive coating 11 respectively coating to include biggest size of element be 25 microns bulky grain 21, biggest size of element is 20 microns a granule 23, the light diffusion layer of diffusion resin 22 and to contain biggest size of element be 13 microns particle 31, the adherent layer light diffusion layer of antiseize resin 32, dry, obtain optical diffusion as shown in Figure 2, test result sees Table 1.
Comparative Examples
With crystalline polyester resin crystallizing and drying under 170 ℃ of conditions, send into corresponding extrusion system then, under 280 ℃, melt extrude, curtain coating is to chilling roll, through the supported body 10 of orientation stretching, then on support 11 respectively the coating comprise biggest size of element be 20 microns light granule proliferation 21, the diffusion resin 22 light diffusion layer and contain the adherent layer that biggest size of element is 8 microns antiseized particles 31, antiseize resin 32, dry, obtain optical diffusion as shown in Figure 1, test result sees Table 1.
Table 1: properties of product test data table
In the table:
1. adhesive rate method of testing:
Pressing GB/T9286 " paint and varnish, the cross cut test of paint film " measures.
2. thickness testing method:
Use the LG-1 vertical optical meter of Shanghai Optical Instrument Factory No.2 to test.
3. transmittance/mist degree method of testing:
Use the WGT-S of Shanghai Precision Scientific Apparatus Co., Ltd transmittance/mist degree analyzer test.
By data in the table as can be seen, the optical diffusion that the utility model provides, light penetration height, light scatter good evenness, fastness excellence.