JPH09119079A - Production of print fabric having reflective ability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a print fabric having reflective ability by uniformly embedding glass beads by their half spheres in the surface of polyethylene film laminated on a heat-resistant film, providing a metal thin film thereon, thermally pressing the metal thin film through an adhesive to the fabric and releasing the resultant laminate. SOLUTION: The polyethylene film face of a laminate obtained by laminating a polyethylene film to a polyester film having >=150 deg.C heat resistance is softened by heating and true spherical transparent glass beads are scattered as a monolayer so as to be packed in nearly densest density and embedded by their own weight till their half-spheres. Then, aluminum is subjected to vacuum deposition on the exposed face of glass beads to provide a metal thin film having light reflecting property, and an isocyanate-based adhesive having 0.5-10% NCO content is printed in 10-70μm dried film thickness on the metal thin film surface and thermally pressed to a fabric such as polyester round knitted jersey before solidifying the adhesive and aged, and the laminated film and the non-print part are released and removed to provide the objective print fabric having reflective ability.

Description

Detailed Description of the Invention

[0001]

2. Description of the Related Art Conventionally, in order to ensure safety especially at night, a retroreflective material having excellent visibility at night has been widely used. This type of retroreflective material includes a glass bead type and a non-bead type, and a glass bead type having good retroreflective performance of glass beads is mainly used. The glass bead type includes a closed type in which the glass beads are buried in the resin layer and an open type in which approximately half of the glass beads are exposed in the air.

The main uses of these retroreflective materials are:
A retroreflective sheeting, which is provided with an adhesive layer on the back side and attached to other objects, is used for road signs, while a retroreflective sheeting, which is used by backing a fiber cloth on the back side, is used by police and construction. It is used for safety clothing of related persons. Recently, due to heightened awareness of safety, retro-reflective fabrics have been sewn onto windbreakers, training wear, etc. as a measure to prevent traffic accidents for pedestrians and joggers at night. Has been done.

However, a general closed type retroreflective cloth has a surface resin layer, a glass bead burying layer,
Focal resin layer, reflective film, adhesive layer, and fiber cloth have a multi-layered structure, so the retroreflective performance during rain is relatively good, but because glass beads are buried in the resin, excellent retroreflectivity is achieved. It has the problems that it is difficult to obtain the reflective performance and the texture is very hard. On the other hand, open type retroreflective cloth is made of glass beads,
It has a relatively simple structure of reflective film, adhesive layer, and fiber cloth. Since the glass beads are exposed in the air, it has superior retroreflection performance and soft texture compared to the closed type. However, it does not have a sufficient feeling for clothing applications, and glass beads and the like fall off during home washing and dry cleaning, resulting in a decrease in retroreflective performance and a defective appearance. Therefore, the advent of a retroreflective print cloth having a soft texture and excellent wash durability has been desired.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned situation, and is of an open type having a soft texture and excellent retroreflective performance and washing durability thereof. It is intended to produce a retroreflective print cloth.

[0005]

The present invention attains the above object and has the following constitution. That is, the present invention provides a "first step of spreading true spherical transparent glass beads on the polyethylene film surface of a laminate of a film having a heat resistance of 150 ° C. or more and a polyethylene film, and burying the upper hemisphere of the glass beads, and The second step of applying a light-reflective metal thin film, printed with an isocyanate adhesive with an NCO content of 0.5-10%, and thermocompression-bonded with the fiber cloth before the adhesive solidifies. And a fourth step of peeling and removing the laminate and the non-printed portion, and a method for producing a retroreflective print cloth having excellent washing durability.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the method of the present invention, first, as the first step, 150
A spherical spherical transparent glass bead is sprinkled on the polyethylene film surface of a laminate of a film having a heat resistance of ℃ or more and a polyethylene film, and the upper hemisphere of the glass bead is embedded. As the film having a heat resistance of 150 ° C. or higher, a film that can withstand practical use without abnormal expansion / contraction, thermal softening, etc. even at a temperature of 150 ° C. or higher, specifically, a polyethylene terephthalate film, Examples include polychlorotrifluoroethylene film, polytetrafluoroethylene film, nylon- or phenol-resin film and paper reinforced with fillers such as glass fiber. However, in view of cost and simplicity, the method of the present invention is used. It is best to use a polyethylene terephthalate film.

Examples of the polyethylene film used in the present invention include a high density polyethylene film, a medium density polyethylene film, a low density polyethylene film, and an ethylene vinyl acetate copolymer film. In the method of the present invention, the heat softening point is low. It is optimal to use a low-density low-density polyethylene film. In the method of the present invention, a laminate of the above-mentioned film having a heat resistance of 150 ° C. or more and a polyethylene film (hereinafter referred to as a process film) is used. As a method of forming this process film, a polyethylene film is treated by corona discharge treatment. After activation by plasma discharge treatment or the like, lamination with an adhesive or the like can be performed.

In the present invention, the upper hemisphere of the spherical transparent glass beads is formed on the polyethylene film surface of the above process film,
That is, 40 to 60% of the glass bead diameter is densely buried. The spherical transparent glass beads here are TiO ₂ , S
iO ₂ , BaO, ZnO, CaO, K ₂ O, PbO, N
a large number of transparent glass beads obtained by spheroidizing glass agglomerates having a refractive index of 1.8 to 2.0 composed of one or more kinds of a ₂ O or the like by a spouting spheroidizing method, a rotary kiln spheroidizing method, etc., The transparent glass beads are preferably Ti
Refractive index mainly composed of O ₂ , BaO, ZnO 1.90 to 1.
94 glass beads are mainly used.

As means for burying the glass beads,
After the glass beads were adhered in a close-packed state on the polyethylene film surface that was heat-softened at a temperature of 80 to 150 ° C., 15
The glass beads are submerged by their own weight at a temperature of 0 to 200 ° C., or they are appropriately embedded by a method such as pressing down with pressure. Buried rate of glass beads is less than 40% or 60%
With the above, the exposure ratio of the transparent glass beads to the air when the process film is peeled off is less than 40% or 60%.
% Or more and less than 40%, the retroreflective performance is inferior, and particularly when the incident angle of light is large, the angle characteristic is deteriorated, and when it is 60% or more, the glass beads easily fall off from the adhesive layer described later, Inferior in durability. The spherical diameter of the glass beads used in the present invention may be 20 to 100 µm. If the spherical diameter is less than 20 µm, the retroreflective performance is deteriorated, which is not preferable. On the other hand, if the spherical diameter exceeds 100 µm, the resulting fabric is obtained. Is not preferable because it increases the thickness and hardens the texture.

In the present invention, as the second step, a metal thin film having light reflectivity is applied from the top of the glass beads by burying the upper hemisphere. As a method for providing the light-reflective metal thin film, a light-reflective metal such as aluminum, silver, gold, or platinum may be formed by a processing method such as vacuum deposition or sputter deposition. For thin film processing, under high vacuum of about 10 ^-2 Torr or more, a method of heating and evaporating and adhering a metal by using a vacuum vapor deposition machine, and sputtering deposition with a metal as a target using an ion beam or magnetron type sputtering device The method of applying aluminum may be appropriately adopted, but vacuum evaporation of aluminum is optimal in view of cost and ease of processing. The vapor deposition film thickness is preferably 300 angstroms or more, more preferably 500 angstroms or more. If the film thickness is 500 angstroms or more, it is possible to totally reflect almost no light.

In the present invention, in the third step, an isocyanate adhesive having an NCO content of 0.5 to 10% is printed on the metal thin film surface, and the fiber cloth and thermocompression bonding are performed before the adhesive is solidified. To do. The isocyanate adhesive used here has an isocyanate group in the molecule of two or more functional groups, and specifically includes 2,4-toluene diisocyanate, 2.6-toluene diisocyanate, and methylenebis (p-phenylene diisocyanate). ), 1.6-
Hexamethylene diisocyanate, isophorone diisocyanate, 1.5-naphthylene diisocyanate, ethylbenzene-α-2 diisocyanate, 4.4 '/ 4'
Examples thereof include addition reaction products of a monomer or oligomer such as triphenylmethane triisocyanate and a compound having active hydrogen (eg, trimethylolpropane, glycerin, polyethylene glycol).

The above-mentioned isocyanate-based adhesive is of a form in which even if the isocyanate group is in a free form, it is stabilized by adding phenol, methylethylketoxime, etc., and the isocyanate group is expressed by the subsequent heat treatment. In addition, additives such as fillers and other substances that do not react with isocyanate groups may be added to these. The form of the adhesive may be solvent-free or solvent-based, and may be appropriately selected depending on workability and application. The content of NCO, which is a reaction residue in the isocyanate compound, is preferably in the range of 0.5 to 10%. When it is less than 0.5%, the washing durability of the print cloth is not improved so much, and when it is more than 10%, the texture of the retroreflective print cloth becomes too hard, and cracks easily occur on the surface due to wearing, washing and the like. The NCO content rate here is
It is a numerical value represented by the following formula. NCO content = (number of NCO residues in molecule × 42) / molecular weight × 100

In the present invention, the isocyanate adhesive is printed so that the dry film thickness is 10 to 70 μm. When the dry film thickness is less than 10 μm, the texture is soft, but the washing durability is deteriorated, and when it is 70 μm or more, the printing mold becomes blurred and the texture becomes hard, which is not preferable. As a printing method, a generally known printing device may be used, and specific examples thereof include a gravure roll coater, a flat screen printing machine, and a rotary screen printing machine.

After printing the isocyanate adhesive, in the present invention, thermocompression bonding is performed with the fiber cloth before the adhesive is solidified. If the adhesive is solidified and then thermocompression bonded, the bite into the fiber cloth is weakened, and as a result, it becomes difficult to obtain excellent adhesive strength. The temperature of thermocompression bonding is preferably 170 ° C. or lower, although it depends on the time and method of pressure bonding. 170 ° C
If the thermocompression bonding is performed at a temperature above 100 ° C., the shrinkage of the process film, especially the polyethylene film, becomes large, which is not preferable. In this thermocompression bonding, there is no problem even if the fiber cloth is preliminarily crimped and then thermocompression bonded, and the crimping method may be carried out by using an ordinary crimping device such as a roll press or a flat press.

As the fiber cloth used as the base cloth in the present invention, polyamide synthetic fibers represented by nylon 6 and nylon 66, polyester synthetic fibers represented by polyethylene terephthalate, polyacrylonitrile synthetic fibers, polyvinyl alcohol synthetic fibers. Examples include fibers, semi-synthetic fibers such as triacetate, and woven fabrics, knitted fabrics, non-woven fabrics and the like made of blended fibers such as nylon 6 / cotton and polyethylene terephthalate / cotton. After thermocompression bonding with the fiber cloth, aging is performed for a certain period of time, and then, as a fourth step, the process film and the non-printed portion are peeled off at the same time, whereby the retroreflective print cloth of the present invention can be obtained. The present invention has the above configuration.

[0016]

[Function] Since the isocyanate-based adhesive exhibits extremely strong chemical reactivity with a compound containing active hydrogen, it is directly chemically bonded (primary bond) to a compound having such a functional group.
To give excellent adhesion that is difficult to cut mechanically. When this isocyanate-based adhesive is directly printed on a metal thin film having light reflectivity and subjected to thermocompression bonding, the adhesive firmly adheres to the metal thin film, and since the thickness of the metal thin film is at most submicron order, it has a spherical shape. It also adheres firmly to the transparent glass beads, and as a result, the glass beads and metal thin film are less likely to fall off even during home washing and dry cleaning with turpentine, perchlorethylene, etc., and have good washing durability. A retroreflective printed cloth is obtained. The retroreflective printed cloth according to the method of the present invention has a soft texture, which is obtained by printing the adhesive on the metal thin film and press-bonding it to the inside of the fiber cloth of the adhesive. The result is that the penetration of

[0017]

EXAMPLES The present invention will be described in more detail with reference to the examples below. The measurement and evaluation of the performance of the fabrics in the examples were carried out by the following methods. (1) Washing test 10 washes in accordance with JIS L-0217 (method 103), 2
It was washed 0 times. (2) Retroreflective performance 10 before the washing and the washing test in the above (1)
Regarding the sample after washing and 20 washing, JIS Z-9117
The reflection brightness (observation angle: 0.33 °, incident angle: 5 ° and 40 °) was measured according to the above.

(3) Change in appearance 1 according to the sample before washing and the washing test in the above (1)
The appearance change of the sample after 0-washing and 20-washing was visually observed, and a relative evaluation was made in the following three stages. ○; Almost no change in appearance △; Slight change in appearance ×; Large drop of glass beads and aluminum vapor deposition film, poor appearance (4) Feeling The following three-level evaluation was performed by handling. ○; Soft △; Slightly hard ×; Hard

Example 1 First, a 22-gauge circular knit fabric was knitted with a Kanoko fabric using 150 denier / 36 filaments of polyester filament as a fiber cloth for a base cloth, and was scoured and dyed by an ordinary method (Japaneseization). Yaya Co., Ltd., disperse dye Kayalon Fa
st Yellow GL 1% owf) was performed.

Next, a polyethylene terephthalate film having a thickness of 50 μm and a low density polyethylene film having a thickness of 40 μm are prepared. A corona discharge treatment machine (manufactured by Kasuga Denki Co., Ltd.) is used for the polyethylene film, and its high frequency power supply device is used. HFSS-101 type of 30 KHz, III type electrode is used for the discharge electrode, and the discharge energy amount is 2
Corona discharge treatment was performed at 0000 joules / m ² .
On the other hand, for the polyethylene terephthalate film, using a gravure coater, Hibon 7031L (manufactured by Hitachi Chemical Polymer Co., Ltd., the main solvent is toluene, and the solid content concentration is 2).
0% low viscosity polyester adhesive solution) 15 g / m
² coating, after drying, subjected to corona discharge treated surface and laminate the polyethylene film to obtain a casting film.

Furthermore, first, in the above process film,
HI-53-105S (manufactured by Nippon Electric Glass Co., Ltd., TiO ₂ , BaO having a refractive index of 1.9 as a main component) was applied to the softened polyethylene film side by heat treatment at 10 ° C. for 3 minutes.
2, Transparent glass beads for retroreflection with a diameter of about 60 μm)
Was adhered in a single layer in a substantially close packed state, and then heat-treated at 170 ° C. for 3 minutes to bury the glass beads in the softened polyethylene film layer by its own weight by about half (about 30 μm). Then, a reflective film was formed by vacuum-depositing aluminum metal with a film thickness of 800 angstrom on the exposed surface of the glass beads under a high vacuum of 10 ⁻⁴ Torr using a vacuum evaporation machine.

Then, polyanate 955H (manufactured by Toyo Polymer Co., Ltd., isocyanate adhesive solution with NCO content of 1.5% and solid content of 50%) was applied to the aluminum vapor-deposited surface with a flat screen printing machine in a 1 cm square. A unit checkered pattern is printed to a thickness of 70 μm (dry film thickness is 35 μm), semi-dried at 100 ° C. for 1 minute, and then hot-pressed at a temperature of 150 ° C. and a pressure of 2 kg / cm ² for 5 seconds, with the above-mentioned fiber cloth. After thermocompression bonding and aging for 2 days, the process film and the non-printed portion were peeled and removed to obtain the retroreflective print cloth of the present invention.

For comparison with the present invention, the following Comparative Examples 1 to 6
Thus, a retroreflective printed cloth for comparison was obtained.

Comparative Example 1 In the step of immersing the glass beads in the polyethylene film layer in the present example (first step), between the induction heating jacket roller (manufactured by Tokuden Co., Ltd.) controlled at 150 ° C. and the metal roll. Nip it at a pressure of 10 kg / cm to bring about 6 glass beads.
A retroreflective print cloth for comparison, in which the glass beads were exposed to about 65% in the air, was obtained by the same method as in this example except that the method of burying 5% was adopted.

Comparative Example 2 Except that the glass beads were buried by about 35% by changing the heat treatment of the process film to 150 ° C. for 2 minutes instead of 170 ° C. for 3 minutes in this example, except for this example. A comparative retroreflective print cloth with about 35% glass bead exposure was obtained by the same method.

[Comparative Example 3] In this example, Polynate 955H of isocyanate adhesive was replaced with Polynate 74
(Toyo Polymer Co., Ltd., NCO content is 10.5%
Then, a retroreflective print cloth for comparison was obtained by the same method as in this example except that the isocyanate adhesive solution having a solid content of 60% was used.

[Comparative Example 4] In this example, an isocyanate-based adhesive, Polynate 955H, was used to prepare NC of the following prescription 1.
A retroreflective print cloth for comparison was obtained in the same manner as in this example, except that the adhesive formulation containing no O group was used. Prescription 1 Mercy 424 100 parts (Toyo Polymer Co., Ltd., polyurethane emulsion adhesive solution) AD-C-65 3 parts (Toyo Polymer Co., Ltd., epoxy crosslinking agent) AD-K-8 2 parts (Toyo Polymer Co., Ltd.) Made, urethane type thickener)

[Comparative Example 5] In this example, a retroreflective reflection for comparison was made in the same manner as in this example except that the print thickness by the flat screen printing machine was changed to 15 μm (dry film thickness was 8 μm). I got a printed cloth.

[Comparative Example 6] In this embodiment, a retroreflective print for comparison is made by the same method as that of this embodiment except that the print thickness by the flat screen printing machine is changed to 150 μm (the dry film thickness is 75 μm). Got a cloth.

The performances of the present invention and the comparative retroreflective print cloth were measured and evaluated, and the results are shown together in Table 1.

[0031]

[Table 1]

As is clear from Table 1, the retroreflective print cloth according to the method of the present invention has excellent reflection brightness and washing durability as compared with Comparative Examples 1 to 6 and has a soft texture. .

[0033]

According to the method of the present invention, a retroreflective printed cloth having excellent retroreflective performance and washing durability can be obtained. Moreover, the retroreflective printed cloth of the present invention is an open type in which the glass beads having a relatively simple structure are exposed to the air in the retroreflective material, so that the retroreflective printed cloth can be easily manufactured at low cost. Furthermore, it is also excellent in the soft texture that is essential as a clothing material.
The retroreflective printed cloth of the present invention is most suitable as a material for safety clothing and sports clothing because of the above excellent performances.

Claims (1)

[Claims] 1. A first step in which a spherical spherical transparent glass bead is spread on the polyethylene film surface of a laminate of a film having a heat resistance of 150 ° C. or more and a polyethylene film, and the upper hemisphere of the glass bead is buried. Second step of applying a light-reflective metal thin film, printing an isocyanate adhesive with an NCO content of 0.5-10% on it, and thermocompression-bonding it with a fiber cloth before the adhesive solidifies A method for producing a retroreflective printed cloth having excellent washing durability, comprising a third step and a fourth step of peeling and removing the laminate and the non-printed portion.