JP2003118297A - Transfer print and tire having the same pasted thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer print ensuring sufficient light emitting brightness and capable of minimizing the use amount of a luminous pigment, and a tire having the same pasted thereon. SOLUTION: A mask layer 4 forming an arbitrary display shape is printed on the surface of an unvulcanized rubber sheet 3 formed by laminating a luminous rubber layer 1 with a thickness of 0.5 mm or more comprising a rubber compounded with the luminous pigment and a substrate rubber layer 2 with a thickness of 0.1 mm or more showing a bright color.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a transfer print for forming a luminous display portion on the outer surface of a tire,
More specifically, the present invention relates to a transfer print capable of ensuring a sufficient emission brightness and minimizing the amount of a phosphorescent pigment used, and a tire to which the transfer print is attached.

[0002]

2. Description of the Related Art Conventionally, it has been proposed to form a luminous display portion on a sidewall portion of a tire for the purpose of improving night visibility and fashionability. As such a technique, Japanese Patent Laid-Open No. 2000-185528 discloses a method in which the conventional white side letter portion is composed of a phosphorescent rubber, and the amount of the phosphorescent pigment used is reduced by devising the composition of the rubber composition. Is disclosed. However, in this method, the rubber package of the side wall part is molded by multicolor extrusion, and this is attached over the entire circumference of the green tire, and after vulcanization, the display part of the side wall part is buffed to expose the phosphorescent rubber. As a result, the luminous rubber of the part other than the display part is completely wasted,
Even if the gauge of the phosphorescent rubber was made thin, there was a limit to the reduction of the amount used.

On the other hand, as a method of arranging the luminous rubber only at a specific position of the tire, it has been proposed to use a transfer print obtained by printing a special ink containing a luminous pigment on a non-contaminated rubber. However, even if the ink contains a phosphorescent pigment, it is not possible to secure sufficient emission brightness because the coating film of the ink itself is thin. Further, when the content of the phosphorescent pigment is increased, there is a drawback that the ink coating film cannot follow the deformation of the tire and cracks easily occur. Therefore, it was not possible to obtain a transfer print with sufficient emission brightness by this method.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a transfer print and a tire to which the transfer print is adhered, which is capable of ensuring a sufficient emission brightness and minimizing the amount of the phosphorescent pigment used. To do.

[0005]

The transfer print of the present invention for achieving the above object has a luminous rubber layer having a thickness of 0.5 mm or more formed by mixing a rubber with a luminous pigment and a bright color. It is characterized in that a mask layer for forming an arbitrary display shape is printed on the surface of an unvulcanized rubber sheet laminated with a base rubber layer having a thickness of 0.1 mm or more.

In the transfer print of the present invention, the luminous rubber layer is formed thick, and the base rubber layer exhibiting a bright color is laminated on the luminous rubber layer. Therefore, based on the luminous pigment contained in the luminous rubber layer. It is possible to secure a sufficient emission brightness. In addition, since the transfer print of the present invention is used by being attached to an arbitrary position on the outer surface of the tire, it is not necessary to dispose the luminous rubber over the entire circumference of the tire as in the conventional case.
Therefore, in forming the luminous display portion on the tire, the amount of the luminous pigment used can be minimized.

In the present invention, the mask layer forming an arbitrary display shape is mainly required to have a function of covering the phosphorescent rubber layer, and thus can be formed as thin as possible. For example, the mask layer may be composed of an ink coating film and have a thickness of about several μm. Further, the mask layer may be made of non-polluting rubber and the thickness thereof may be 0.5 mm or less. If the mask layer is made thin in this way, even if the transfer print is attached to the outer surface of the tire and vulcanized, the display shape such as letters formed by the mask layer will not be greatly deformed by the rubber flow, so that it is a normal tire. The mold can be used to vulcanize a tire with a luminous display.

The thickness of the unvulcanized rubber sheet is preferably 2 mm or less. That is, the light emission luminance is increased by increasing the thickness of the light storing rubber layer and the base rubber layer, but if the thickness is too thick, the influence on the tire increases.

A peelable release sheet is preferably laminated on the mask layer side of the transfer print. By laminating such a release sheet, it is possible to reliably prevent the display shape formed by the mask layer from being deformed or soiled during vulcanization.

As the phosphorescent pigment, it is preferable to use a strontium aluminate-based phosphorescent phosphor. Since the strontium aluminate-based phosphorescent phosphor has a long emission time and a high emission brightness, it is suitable as a phosphorescent pigment for forming a phosphorescent display portion on a tire using a transfer print as a medium.

According to the present invention, there is provided a tire obtained by attaching the above-mentioned transfer print to the outer surface and vulcanizing it.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a transfer print according to an embodiment of the present invention. As shown in FIG. 1, the transfer print according to the present embodiment has a surface of an unvulcanized rubber sheet 3 in which a phosphorescent rubber layer 1 and a base rubber layer 2 are laminated (phosphorescent rubber layer 1
On the side), a mask layer 4 for forming an arbitrary display shape is printed.

The phosphorescent rubber layer 1 is composed of a transparent or semitransparent rubber composition in which a phosphorescent pigment is mixed with rubber.
The thickness is 0.5 mm or more. If the thickness of the light storing rubber layer 1 is insufficient, sufficient light emission luminance cannot be obtained.

As the rubber constituting the luminous rubber layer 1,
Diene rubbers and hydrogenated products thereof [eg polyisoprene rubber (IR), polybutadiene rubber (BR), conjugated diene-aromatic vinyl copolymer (eg SBR), nitrile-conjugated diene copolymer (eg NBR), hydrogen NB
R, hydrogenated SBR], olefin rubber [eg ethylene propylene rubber (EPDM, EPM), maleic acid modified ethylene propylene rubber (M-EPM)], butyl rubber (IIR), isobutylene and aromatic vinyl or diene monomer copolymer Combined, acrylic rubber (ACM), ionomer, halogen-containing rubber [eg Br-IIR, Cl-
IIR, bromide of isobutylene paramethylstyrene copolymer (Br-IPMS), chloroprene rubber (C
R), hydrin rubber (CHC, CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (C
M), maleic acid-modified chlorinated polyethylene (MC
M)], sulfur-containing rubber (for example, polysulfide rubber),
Fluorine rubber (for example, vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing phosphazene rubber) and the like can be mentioned.

On the other hand, a phosphorescent pigment blended in the phosphorescent rubber layer 1
As a strontium aluminate-based phosphorescent fluorescent
Body, eg SrAl₂O_Four: Eu, Dy, Sr_FourAl
₁₄O _{twenty five}: Eu, Nd, SrAl₂O_Four: Eu, m (Sr
_1-xEu_x) O ・ nAl₂O ₃・ YB₂O₃(1 ≦ m ≦
5, 1 ≤ n ≤ 8, 0.001 ≤ x ≤ 0.1, 0.005
≦ y ≦ 0.35) and the like are preferably used. these
The phosphorescent phosphor is 5 to 100 parts by weight per 100 parts by weight of rubber.
It is advisable to mix them in parts by weight. This blending amount is less than 5 parts by weight
And the emission brightness becomes insufficient, and conversely exceeds 100 parts by weight.
And since the emission brightness is saturated, it is useless to mix more than that.
Not only that, but the physical properties of rubber may deteriorate.

To the rubber composition of the luminous rubber layer 1, silica, talc, clay, calcium carbonate or the like can be added as a white filler. Further, for the purpose of diffusely reflecting the light of the phosphorescent phosphor to enhance the emission brightness and enhance the visibility, glass powder, quartz powder, acrylic resin powder or the like may be added to such an extent that light transmission is not hindered.

On the other hand, the base rubber layer 2 is composed of a rubber composition having a light color and has a thickness of 0.1 mm or more. If the thickness of the base rubber layer 2 is insufficient, the original black color of the tire penetrates, and sufficient brightness cannot be obtained. As the rubber constituting the base rubber layer 2, the same rubber as described above can be used. The base rubber layer 2 is colored brighter than black, preferably white, yellow, yellow-green, light blue, silver or the like, and particularly preferably white. The bright color as used herein means a chromatic color or an achromatic color having a lightness V of 6 or more, preferably 7 or more, out of the three attributes of the color specified in JIS Z 8721.

The unvulcanized rubber sheet 3 includes a luminous rubber layer 1 and a base rubber layer 2, and the thickness thereof is preferably 2 mm or less. When the thickness of the unvulcanized rubber sheet 3 exceeds 2 mm, although the emission brightness is high, the influence on the tire balance becomes large when it is attached to the outer surface of the tire and vulcanized. At this time, it is preferable to adopt a method of attaching a transfer print or a rubber sheet of approximately the same weight to the tire facing position.

The mask layer 4 forms an arbitrary display shape such as a character, a design, a picture or a symbol. The mask layer 4 can be composed of an ink coating film. In this case, the thickness of the mask layer 4 is 0.5 mm or less, usually about several μm. Further, the mask layer 4 may be made of non-contaminating rubber. In this case, the thickness of the mask layer 4 needs to be 0.5 mm or less. The non-staining rubber is a rubber composition in which anti-aging agent having a stain property is excluded as much as possible, and specifically, it has no double bond or contains only a very small amount (5% or less). A rubber composition containing 30% by weight or more of rubber in all rubber components. Generally, isobutylene-based rubber and olefin-based rubber are preferably used, but as long as the rubber composition does not substantially cause cracks due to ozone deterioration or bending without blending a pollutant antiaging agent, Needless to say, it is not limited to these.

When the mask layer 4 is thin as described above, even if the transfer print is attached to the outer surface of the tire and vulcanized, the display shape formed by the mask layer 4 is not largely deformed. In other words, in transfer printing, if the phosphorescent rubber layer is thickened and characters are to be formed by the phosphorescent rubber layer, it is difficult to create characters with thickness, and the characters flow and are distorted. Although it is easy, if the mask layer 4 is responsible for contour formation, these disadvantages can be avoided.
As a result, it is possible to form a clear display shape such as a character while ensuring good light emission brightness based on the thick phosphorescent rubber layer 1.

Since the mask layer 4 shields the light emitted from the light-accumulating rubber layer 1, the shielding form may be either a positive type or a negative type, and its color is also particularly limited. is not. for that reason,
The configurations as shown in FIGS. 2 to 5 are possible. In FIG. 2, a mask layer 4 made of a black ink coating film is provided on the surface of the unvulcanized rubber sheet 3 so as to cover portions other than characters. Figure 3
Is a mask layer 4 composed of a white ink coating film provided on the surface of the unvulcanized rubber sheet 3 so as to cover portions other than characters. FIG. 4 shows a mask layer 4 made of black uncontaminated rubber on the surface of the unvulcanized rubber sheet 3 so as to cover portions other than characters.
Is provided. In FIG. 5, a mask layer 4 made of a black ink coating film is provided on the surface of the unvulcanized rubber sheet 3 so as to cover the character portion. In the case of FIGS. 2 to 4, the character portion emits light in a dark place. In the case of FIG. 5, a portion other than the letters emits light in the dark.

A peelable release sheet (not shown) may be laminated on the mask layer 4 side of the transfer print. As the release sheet, heat-resistant release paper, polyester film, or the like can be used. By laminating such a release sheet, it is possible to reliably prevent the display shape formed by the mask layer 4 from being deformed or soiled during vulcanization.

The above-mentioned transfer print is attached to an arbitrary position on the outer surface of the green tire, for example, a sidewall portion, and then inserted into a mold together with the green tire and vulcanized in a normal vulcanization process. . As a result, for example, the pneumatic tire shown in FIG. 6 is obtained. The pneumatic tire T has a phosphorescent display portion X on the sidewall portion.

In the transfer print, the luminous rubber layer 1 is thick, and the base rubber layer 2 having a bright color is laminated on the luminous rubber layer 1, so that the luminous pigment contained in the luminous rubber layer 1 is used. It is possible to secure sufficient emission brightness. Moreover, since the mask layer 4 is formed thin, a clear display shape can be maintained even after the vulcanization step. Moreover, when transfer printing is used, it is not necessary to dispose the phosphorescent rubber over the entire circumference of the tire as in the conventional case, so the amount of phosphorescent pigment used should be minimized when forming the phosphorescent display portion on the tire. You can Further, since the buffing step is not required, the tire manufacturing cost does not increase.

[0026]

[Examples] Examples 1 to 5 in which a tire size is 205 / 65R15 and a luminous print portion is formed on a side wall portion by using a transfer print having various laminated structures as shown in Table 1 below and comparison. The pneumatic tires of Examples 1 to 3 were manufactured.

With respect to these test tires, the emission brightness of the display portion was evaluated. In the emission brightness test, the test tire was placed on the floor with the surface with the phosphorescent transfer print attached in the dark room, and the JI from 1 m directly above the sidewall surface.
Light of 200 lux from the common light source D65 specified in SZ 8720 was irradiated for 30 minutes, and the brightness 10 minutes after the light was turned off was visually confirmed. The result was evaluated based on the following evaluation criteria.

[0028] ◎: Very bright ○: You can clearly see the light △: It is dark, but you can see the light ×: Light cannot be confirmed

[0029]

[Table 1]

As shown in Table 1, in Example 1, black ink was printed as a mask layer on the surface of the light-accumulating rubber layer, but light was clearly confirmed. In Example 2, white ink was printed as a mask layer on the surface of the light-accumulating rubber layer, but light was clearly confirmed. In Example 3, since the thickness of the light storing rubber layer was thicker than that in Example 1, the brightness was further improved. In Example 4, non-contaminating rubber was stuck as a mask layer on the surface of the light-accumulating rubber layer, but light could be clearly confirmed. In Example 5, the thickness of the light-storing rubber layer was thinned to the lower limit of the specified range, but light could be clearly confirmed.

On the other hand, in Comparative Example 1, the luminance was insufficient because the thickness of the luminous rubber layer was smaller than the lower limit of the specified range. In Comparative Example 2, it was difficult to confirm the light emission because the base rubber layer had a dark color. In Comparative Example 3, since the base rubber layer was not provided, the original black color of the tire was transparent and light could not be confirmed.

[0031]

As described above, according to the present invention, a phosphorescent rubber layer having a thickness of 0.5 mm or more formed by mixing a rubber with a phosphorescent pigment, and a light-colored rubber layer having a thickness of 0.1 mm or more. Since a transfer print is formed by printing a mask layer that forms an arbitrary display shape on the surface of the unvulcanized rubber sheet laminated with the base rubber layer of, the light emission is sufficient based on the phosphorescent pigment contained in the phosphorescent rubber layer. It is possible to secure the brightness, and further, when forming the luminous display portion on the tire, it is possible to minimize the amount of the luminous pigment used.

[Brief description of drawings]

FIG. 1 is a perspective view showing a transfer print according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a transfer print according to another embodiment of the present invention.

FIG. 3 is a perspective view showing a transfer print according to still another embodiment of the present invention.

FIG. 4 is a perspective view showing a transfer print according to still another embodiment of the present invention.

FIG. 5 is a perspective view showing a transfer print according to still another embodiment of the present invention.

FIG. 6 is a side view showing a pneumatic tire obtained by attaching the transfer print of the present invention to a sidewall portion and vulcanizing it.

[Explanation of symbols]

1 Luminescent rubber layer 2 Base rubber layer 3 Unvulcanized rubber sheet 4 Mask layer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3B005 EA20 EB01 EC11 FA05 FB23                       FB25 FB61 GA01 GB01                 4F100 AA33A AA33H AN00A AN00B                       AN00C AR00D BA03 BA04                       BA07 BA10B BA10C BA10D                       BA15 CA13A EC04 EJ06                       EJ91D GB32 HB31C JL06C                       JL10B JL14D JN13 JN13A                       JN13H YY00A YY00B                 4F203 AA45 AB12 AH20 DA11 DB01                       DB26 DC11

Claims (6)

[Claims] 1. An unvulcanized structure in which a phosphorescent rubber layer having a thickness of 0.5 mm or more prepared by mixing a rubber with a phosphorescent pigment and a base rubber layer having a thickness of 0.1 mm or more and exhibiting a bright color are laminated. Transfer printing in which a mask layer that forms an arbitrary display shape is printed on the surface of a rubber sheet. 2. The transfer print according to claim 1, wherein the mask layer is composed of an ink coating film. 3. The mask layer is made of non-polluting rubber,
The transfer print according to claim 1, wherein the thickness is 0.5 mm or less. 4. The transfer print according to claim 1, wherein a peelable release sheet is laminated on the mask layer side. 5. The transfer print according to claim 1, wherein the phosphorescent pigment is a strontium aluminate phosphorescent phosphor. 6. A tire obtained by sticking the transfer print according to claim 1 on an outer surface thereof and vulcanizing the transfer print.