Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
2001-08-27
2003-07-15
Mayes, Curtis (Department: 1734)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S239000, C156S289000
Reexamination Certificate
active
06592700
ABSTRACT:
BACKGROUND OF THE INVENTION
1 Field of the Invention
The present invention relates to a method for preparing retro-reflective sheet with high abrasion resistance which is especially formed according to the following process: on the pattern releasing paper, the first coating layer one component PU resin mixed with reflective particles is coated initially; after drying, the second coating layer two component PU adhesive agent is coated; after being dried, a kind of paste is coated on it; finally, substrate is adhered. After drying and curing, pattern paper is divested from the resin, while solvent is used to solve part of the PU resin, leaving reflective particles exposed and hardened, forming final product. The material produced characterized in high abrasion resistance and using soft material as substrate. In accordance with the invention, the material is well suited to commercial uses like coat, vest, shoes, cap, poster, and the like.
2. Description of the Prior Art
Many patents have been disclosed for composition of retro-reflective material layer and the producing method thereof in U.S. Pat. Nos. 2,432,928, 2,440,584, 2,543,800, 2,397,702, 4,104,102, and the like, wherein retro-reflective plate containing one layer of glass beads is mentioned. Various retro-reflective layer invented in these U.S. Patents serve various commercial and industrial fields, such as mark of highway, traffic retro-reflective plate, and the like, which posses the property of reflecting the ray incident to the main part of the sign, and ray reflected will actually go along the original route, returning to source of the ray. Viewing from the aspect of applying the laminate structure of the retro-reflective plate, it's important to have excellent optical transparence, which make the rays be reflected efficiently when rays entering into the laminate structure with a relative small angle. So a flexible layer structure will benefit the print and printing ink to deposit, and benefit each laminate to bond closely within the layer structure, presenting the feature of weather resistance and glass beads being fixed firmly on the laminate structure.
OBJECTS OF THE INVENTION
Most commercially available retro-reflective materials have good retro-reflective effect, but fail to be abrasion resistive, and glass beads contained in the retro-reflective materials frequently divest off after couple of rubbing. The reason is that before the substrate is hardened, the glass beads just spreads on the resin, being fixed on it physically. After hardening, the fixation is not so strong between the resin and the glass beads that the retro-reflective materials fail to be abrasion resistive. Additionally, hardened resin simply arranges in plain style, not perfect for retro-reflective performance. In present market, the retro-reflective material is limited to serving as highway mark, traffic retro-reflective plate and industrial safety sign for the reason that the substrate is made from hard material. Never see any retro-reflective materials suitable for any commercial fields like coat, vest, shoes, cap, poster made from soft substrate in the market.
SUMMARY OF THE INVENTION
For these reasons, after dedicating study and research, the invention presents a process as following: initially coating the first coating layer one component type polyurethane (PU) resin mixed with glass beads on the releasing paper with embossed grain; after drying, further coating the second coating layer two component type PU resin containing colorant, then drying it; above this layer, coating a kind of paste; finally, adhering the substrate; after pre-drying and curing, divesting releasing paper from the layer structure; finally, using solvent to solve the divested layer structure, leaving glass beads exposed and hardened, forming a retro-reflective material with glass beads being firmly fixed and characterized in abrasion resistance.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following is a detailed description of the invention.
The primary technical characteristics of the invention is using the first coating layer one component type PU resin in appropriate weight as the matrix resin of the retro-reflective material. It's necessary for the resin to apply a balance structure to exhibit excellent resistance to abrasion, heat adhesion and corrosion. The first coating layer should apply one component type PU having an excellent resistance to heat, to benefit subsequently drying and curing which are useful for heat-resistance. Generally, the key of increasing heat resistance of the PU resin is to enhance the cohesive strength, for example, to increase the content of hard segment.
Although PU resin with increased content of hard segment has fine heat-resistant performance, some problems still exits, for example, during processing of the releasing paper and the second coating two component type PU resin, especially when lamination process (referring to the process of coating the second layer on the first layer) is carried out in a short heating period and under incomplete drying, full heat-resistant performance has not be imparted to various layer.
To eliminate the history problem of not fully imparting heat-resistant performance, one object of present invention is to provide a kind of one component type PU resin as the first coating layer, instead of using cross-linking agent, therefore when lamination process is carried out under incomplete drying, one component type PU resin with heat-resistant performance can be obtained.
PU resin used in one component PU resin of present invention comprises polyol component, poly isocyanate component and organic solvent.
Examples of preferred polyol component are polyester polyol and polyether polyol. The former can be produced in addition reaction by reacting ethylene oxide and/or propylene oxide with small molecular weight polyol such as glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2 butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, hexamethylene glycol, hydrogenated bisphenol A, bisphenol A, trihydroxy methyl propane, glycerin or polyethylene glycol, polypropylene glycol, polyethylene/polypropylene glycol, poly caprolactone polyol, poly alkene polyol, polybutadiene polyol. The latter can be produced by reacting polyol with polybasic carboxylic acid. Suitable polybasic carboxylic acid can be aliphatic, alicyclic, aromatic or heterocyclic, preferably substituted by halogen atom and/or unsaturated polyester. Preferred polyester polyol includes glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2-&bgr;-hydroxybutylene glycol, 1,6-hexamethylene glycol, 1,7-heptamethylene glycol, 1,8-octylene glycol, 1,12-dodecane glycol, 1,18-octadecane glycol, neopentyl glycol, hexamethylene glycol, bis(1,4-hydroxy methyl) cyclohexane, 2,2-bis(4-hydroxy cyclohexyl) propane, 2,2-(bis-&bgr;-hydroxy ethoxy) phenyl propane, 2-methyl-1,3-butyleneglycol,3-methyl-1,5-pentamethylene glycol, 2,2,4-trimethyl-1,6-hexamethylene glycol,2,4,4-trimethyl-1,6-hexamethylene glycol, glycerin, 1,1,1-trihydroxy methyl ethane, 1,2,6-hexane triol, 1,2,4-butatriol, tris-(p-hydroxyethyl) trimeric isocyanate, isoamyl tetra-alcohol, mannitol, sorbitol, diethylene glycol, dipropylene glycol, bibutylene glycol, xylyl glycol and hydroxy valeric neopentyl glycol ester. Abovementioned polybasic carboxylic acid can be succinellite, hexane diacid, 1,8-octanedioic acid, nonanedioic acid, decanedioic acid, phthalic acid, p-phthatic acid, m-phthatic acid, trimesic acid, pyromellitic acid, tetrahydric phthalic acid, hexahydric phthalic acid, hexahydric terephthatic acid, dichloro phthalic acid, tetrachloro phthalic acid, methylene bridge tetrahydric phthalic acid, dibasic fatty acid, pentanedioic acid, maleic acid, fumaric acid and anhydride thereof, dimethy p-phthatiate ester, p-phthatic acid bidiol ester. During preparation of polyester polyol, use any mixture of abovementioned polyol mixing with any mixture of abovementioned poly dicarboxylic acid and/or
Chou Yung-Hsiang
Lin Chih-Chen
Lin Mong-Ching
Wang Ching-Tang
Bacon & Thomas
Mayes Curtis
San Fang Chemical Industry Co. Ltd.
LandOfFree
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