JP2533386B2 - Heat resistant printing substrate and label - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat-resistant printing substrate having an inorganic powder layer on one surface of a heat-resistant substrate, which has excellent reflectance and good pattern visibility, etc. And a label using the same.

Background of the Invention As the production system shifts to high-mix low-volume production, products made of heat-resistant plastics, metals, glass, fired ceramics, etc., or fired ceramics used up to now as identification labels used to manage semi-finished products and parts If you use a substrate type consisting of stainless steel, enameled body, etc., it may be due to the problem of lack of curved surface stickiness due to rigidity, the problem of lack of flexibility in forming the identification label due to the difficulty of patterning on site, screwing etc. There is a need for a new type of identification label because it takes time to fix and there is a problem of lack of simple fixability.

The basic performance required for a new type of identification label is
High visibility of pattern due to high density of pattern and reflectance, abrasion resistance, flexibility, flexible label forming property, good preservation of applied pattern after heating or after chemical treatment, heat resistance, chemical resistance In some cases, simple adhesion is required from the standpoint of fixing work, and moderate non-polishing is also required from the viewpoint of preventing the pattern from being disturbed by coloring due to shavings when metal comes into contact. Many.

2. Description of the Related Art Conventionally, as an identification label that responds to the above, there is an identification label obtained by applying a pattern to a substrate such as a plastic film such as polyethylene terephthalate or a metal deposit thereof, paper, or the like with a printer such as a bar impact printer or a thermal transfer printer. Proposed. However, the heat resistance of the substrate is such that it can withstand the heating temperature of the printer, and there is a problem in that the heat resistance is relatively poor.

As a base material, there is also known a base material in which a heat resistant base material is provided with an inorganic powder layer which is shaped by an organic binder made of a mixture of polyimide and a fluoropolymer (JP-A-62-198490). However, there is a problem in that the reflectivity is poorly expressed, and the reflectivity is greatly reduced due to coloring due to alteration of the polyimide. In the case of a white-based black barcode label or the like, if the reflectance of the base material is low, it causes a misreading and becomes a fatal problem.

Means for Solving the Problems The present invention provides a heat-resistant printing base material having the above-mentioned required basic performance and overcoming the above-mentioned problems, and a label using the same.

That is, the present invention comprises an inorganic powder layer formed on one side of a flexible heat-resistant base material with an organic binder, wherein aromatic polyamide is used as the organic binder, and the content of the inorganic powder in the inorganic powder layer is A heat-resistant printing substrate characterized by having a content of 30 g / m ² or more, and a label characterized by comprising an ink pattern formed on an inorganic powder layer in the heat-resistant printing substrate. is there.

By forming a heat-resistant printing substrate with the above-mentioned inorganic powder layer and a heat-resistant substrate, it can be a flexible substrate and has curved surface followability, and also has excellent heat resistance and chemical resistance. Further, a high-density pattern can be satisfactorily applied to the inorganic powder layer, and the preservation of the applied pattern after heating or after chemical treatment is excellent. Initial reflectance (890nm) 40% or more, 300 ℃
× The reflectance and the maintainability thereof are excellent such that the reflectance decreases after heating for 1 hour within 30%. Further, an ink pattern can be arbitrarily applied to the inorganic powder layer by an appropriate printing method, and the pattern has excellent visibility and scratch resistance. In addition, when the inorganic powder layer has a hardness of HB to 6H, it has a proper non-abrasive property in which it is not colored with shavings of metal or the like, or is not colored more than an allowable range. On the other hand, it is easy to give a simple adherence to an adherend by attaching a heat resistant adhesive layer.

Exemplary Components of the Invention The heat-resistant printing substrate of the present invention is a flexible heat-resistant substrate provided with an inorganic powder surface on one side. An example of the structure is shown in FIG. 1 is an inorganic powder layer, and 2 is a heat resistant substrate. Reference numeral 3 is a heat-resistant adhesive layer which is provided as necessary to easily adhere to the adherend.

The inorganic powder layer is formed, for example, by a method of coating a heat-resistant base material with a mixture of a liquid organic binder such as a solution or a melt and an inorganic powder. The layer thickness may be appropriately determined according to the pattern forming method and the like, and is usually 300 μm or less, and particularly 3 to 100 μm. The amount of inorganic powder used is
10 to 2000 parts by weight per 100 parts by weight of organic binder, especially 100
An amount of 0 parts by weight or less is suitable. The amount of inorganic powder used is 10
If it is less than 200 parts by weight, the reflectance is poor, and if it exceeds 200 parts by weight, cohesive failure tends to occur. The content of the inorganic powder in the inorganic powder layer is 30 based on the unit area of the inorganic powder layer determined by the usage ratio of the inorganic powder and the thickness of the inorganic powder layer.
From the viewpoint of reflectance, it is appropriate to set it to g / m ² or more.

Examples of inorganic powders that can be preferably used include titania, silicon carbide, silicon nitride, boron nitride, and alumina.
Ceramic powder such as zirconia, silicon oxide, barium titanate, calcium carbonate, talc, CoO-Al ₂ O ₃ , Ni
_{O 2 -CrO 3, CoO-MnO} 2 -CrO-Fe 2 O 3, MnO 2 such pigments -Cr ₂ O _3, aluminum powder, stainless steel powder, iron powder, nickel powder, chromium powder, silver powder, gold powder such as metal Examples include powder. Among them, titania is preferable, and a combination of titania, calcium carbonate, and talc is preferably used from the viewpoints of reflectance, compatibility with ink (application pattern), printability, adhesion with heat-resistant substrate, non-abrasiveness, and the like. To be In the combined system, it is preferable to use 30 to 90% by weight of titania. The particle size of the inorganic powder used is 100 μm or less, especially 5
0 μm or less is suitable.

As the organic binder, an aromatic polyamide is used from the viewpoints of the reflectance of the inorganic powder layer or its maintainability, heat resistance, moldability, adhesion to the base material, etc., and other organic polymers may be used in combination as necessary. It Examples of organic polymers used in combination are polyimide, polyetheretherketone, polyethersulfone, polyetherimide, polysulfone,
Heat-resistant polymers such as polyphenylene sulfide, polyamide imide, polyester imide, non-aromatic polyamide, parabanic acid resin, fluororesin and epoxy resin,
Hydrocarbon resin, vinyl resin, acetal resin, acrylic resin, styrene resin, polyester resin,
Examples include polyurethane-based resins, rubber-based resins, alkyd resins, and fibrous resins. When another organic polymer is used in combination, the amount of aromatic polyamide used is suitably 50% by weight or more.

In forming the inorganic powder layer, in addition to the curing agent and the cross-linking agent of the organic binder, the adhesion to the heat-resistant substrate is improved, the fixability of the ink pattern is improved, the viscosity of the coating liquid is adjusted, etc. Various additives may be added.

The inorganic powder layer to be formed may have a single-layer structure as shown in FIG. 1 or a two-layer structure as shown in FIG. The two-layer structure is effective for improving various properties, particularly for improving the adhesion with the heat resistant substrate while maintaining the reflectance. In the case of a two-layer structure, it is appropriate to reduce the content of the organic binder in the outer layer 11 and increase the content of the organic binder in the inner layer 12 from the viewpoints of reflectance, adhesion to a base material, pattern impartability and the like. Generally, the content of the organic binder in the outer layer is 10 to 80% by weight, and the content of the organic binder in the inner layer is 30% by weight or more. Thickness of outer layer is 2μm or more, especially 10μm or more, inner layer is 1μm
m or more, and especially 5 μm or more, and the thickness ratio is generally 1 to 10 based on the outer layer / inner layer. In addition, the content of the inorganic powder is 30 g / m ² or more based on the total area of the inorganic powder layer including the inner and outer layers, and in particular 40 g / m ² or more, and the reflectance may be formed. It is more suitable than

The surface roughness (Ra) of the inorganic powder layer is preferably 0.01 to 5 μm, and more preferably 0.05 to 1.5 μm from the viewpoint of improving the fixability of the applied pattern. If the roughness is less than 0.01 μm, the applied pattern may bleed by heating, and if it exceeds 5 μm, the applied pattern may be chipped or missing.

The hardness of the inorganic powder layer is HB ~
6H is suitable. That is, if the hardness is too low, it is easily scratched, but if the hardness is too high, for example, the metal is scraped off when the metal contacts, and the shavings adhere to the inorganic powder layer. Cause of. From this point, a desirable hardness is about H to 5H based on the hardness of the pencil.

As the heat-resistant base material, a flexible one having good heat resistance and thermal dimensional stability is used. Above all, those having a heat resistance of 150 ° C. or higher and a heat shrinkage ratio of 1.5% or less are preferably used. An example thereof is a film made of the heat-resistant polymer exemplified as the organic binder, and a polyimide film is preferable. The thickness of the heat resistant substrate may be appropriately determined, and is generally 500 μm or less, preferably 10 to 200 μm.

An adhesive having good initial tackiness, heat resistance, and chemical resistance is preferably used for forming the heat resistant adhesive layer which is additionally provided if necessary. Examples thereof include acrylic, silicone, and epoxy heat-resistant adhesives. The thickness of the heat resistant adhesive layer provided on the heat resistant substrate is generally 5 to 300 μm, but the thickness is not limited thereto and may be appropriately determined. The heat resistant adhesive layer may be formed by a method of applying the forming agent or a method of forming a sheet of the forming agent in advance and adhering it to the heat resistant base material. The exposed surface of the heat-resistant adhesive layer is covered and protected with a separator or the like, if necessary, and used for pattern formation or the like.

The heat-resistant printing substrate of the present invention can be used as heat-resistant printing paper. In particular, as illustrated in FIG.
The heat-resistant printing base material is molded into an appropriate size and is preferably used as the label base material 4 in an identification label or the like. In FIG. 3, 5 is the inorganic powder layer 1 in the label substrate 4.
In addition, the ink pattern is formed by using a thermal transfer type ink ribbon and a printer.

The label can be formed, for example, by forming a predetermined in-pattern such as a bar code on the inorganic powder layer of the heat resistant printing substrate in the form of a label. Alternatively, the heat-resistant printing substrate may be adhered to an adherend via a heat-resistant adhesive layer, and then a predetermined ink pattern may be formed on the inorganic powder layer. When the heat-resistant printing substrate does not have a heat-resistant adhesive layer in advance, a heat-resistant adhesive layer is applied to the adherend or the heat-resistant printing substrate at an appropriate stage when adhering to the adherend. You can do it. The heat-resistant printing substrate or label adhered to the adherend
Heat treatment at 50 to 400 ° C is desirable in terms of stickiness.

The ink pattern is formed on the inorganic powder layer by any method such as a transfer method using a transfer paper, a thermal transfer method, a dot method, a printing method using various printers such as a bar impact method, and a screen printing method. You may The pattern to be given is arbitrary.

Effect of the invention The heat-resistant printing substrate of the present invention uses an aromatic polyamide as an organic binder, and since the content per unit area of the inorganic powder is 30 g / m ² or more, heat resistance, chemical resistance, In addition to having excellent adhesion to the substrate, it also has excellent reflectance, and is resistant to discoloration even at high temperatures and has excellent maintainability of reflectance.
Furthermore, the preservation of the applied pattern after heating or after chemical treatment is excellent. In particular, when the inorganic powder layer has a two-layer structure, it is excellent in reflectance and adhesion to the substrate. Further, when the hardness of the inorganic powder layer is within a predetermined range, shavings do not occur even if a metal or the like has a suitable non-polishing property,
It has the property of not damaging the pattern by coloring.

Examples Example 1 50 parts titania (parts by weight, the same applies hereinafter), calcium carbonate
30 parts, 20 parts of talc, 25 parts of (total) aromatic polyamide having a viscosity average molecular weight of about 30,000 was kneaded uniformly with a roll mill using 95 parts of N, N-dimethylacetamide to form a paste, which was applied by a doctor blade. Using a machine, it was cast on one surface of a polyimide film having a thickness of 50 μm and dried to form an inorganic powder layer having a thickness of 25 μm (inorganic powder content: 50.3 g / m ² ; calculated from specific gravity, the same applies hereinafter). Its surface roughness is R
It was 0.12 μm.

Next, on the other surface of the polyimide film, an epoxy adhesive layer having a thickness of 10 μm and containing bisphenol A type liquid epoxy resin (molecular weight 380) as a main component is formed, and is covered and protected by a separator to provide a heat-resistant printing substrate. I got the material.

A label base material of a predetermined size is cut out from the heat resistant printing base material, a predetermined bar code pattern is formed on the inorganic powder layer through a bar impact printer and an ink ribbon to obtain a label, and the separator is peeled off. This was attached to a glass / epoxy substrate having a thickness of 1 mm and heat-treated at 300 ° C. for 1 hour.

In the above, the initial reflectance (890 nm, the same applies hereinafter) of the inorganic powder layer was 83%, and the decrease in reflectance due to heat treatment was 13%.
%Met. The preservation of the applied pattern after the heat treatment was also good.

Comparative Example 1 In place of the (whole) aromatic polyamide, an inorganic powder layer (thickness: 25 μm, content of inorganic powder: 29.1 g / m ² ) using 60 parts of polyimide and 28 parts of fluoropolymer was formed. A substrate for printing and a label were obtained according to 1., adhered to a glass / epoxy substrate, and heat-treated at 300 ° C. for 1 hour.

In the above, the initial reflectance of the inorganic powder layer is as low as 65%, the inorganic powder layer is discolored by heat treatment, and the reflectance is 15%.
Fell.

Example 2 (total) aromatic polyamide content of 18% by weight and thickness
15 μm outer layer and 95% (total) aromatic polyamide content
A heat-resistant printing substrate was obtained according to Example 1 except that an inorganic powder layer having a two-layer structure composed of an inner layer having a weight percentage of 10 μm was used (total content of inorganic powder was 32.4 g / m ² ).

Regarding the inorganic powder layer in the heat-resistant printing substrate JI
When a cross-cut test was conducted using SK 5400, the evaluation was
It was 10 points.

Example 3 50 parts of titania, 20 parts of calcium carbonate, 30 parts of talc, and 25 parts of (total) aromatic polyamide having a viscosity average molecular weight of about 30,000 were used as N,
A slurry obtained by mixing 125 parts of N-dimethylacetamide was cast on one side of a 25 μm-thick polyimide film with a doctor blade type coating machine, and dried to have an inorganic powder layer (thickness of inorganic powder of 30 μm). Content 60.6g /
m ² ) was formed. The surface roughness was 0.1 μm, and the hardness with a microhardness meter (Hv) under a load of 10 g was 18.33 kg / mm ² .

Next, a 10 μm-thick epoxy adhesive layer containing bisphenol A type liquid epoxy resin (molecular weight 380) as a main component is formed on the other surface of the polyimide film, and is covered and protected by a separator to provide flexible heat-resistant printing. A substrate for use was obtained.

A label substrate of a predetermined size is cut out from the heat-resistant printing substrate, and a label is obtained by forming a predetermined barcode pattern on the inorganic powder layer via a thermal transfer printer or a bar impact printer and an ink ribbon, The separator was peeled off, and this was attached to a glass / epoxy substrate having a thickness of 1 mm and heat-treated at 300 ° C. for 1 hour.

In the above, the initial reflectance of the inorganic powder layer is 72%,
The decrease in reflectance due to the heat treatment was 2%. Also, the preservation of the applied pattern after the heat treatment and after the chemical treatment was good. Furthermore, a cross-cutting test (JIS
The evaluation by K 5400) was 10 points.

In addition, the minimum hardness of a pencil that scratches are formed on the inorganic powder layer under a load of 1 kg is 4H, and if scratches are formed on the tip metal part of a commercial mechanical pencil, the metal should be scraped off. Without scratching, no coloring due to metal shavings was observed on the scratched portion.

Comparative Example 2 Polyimide 60 parts and fluoropolymer 28 as organic binder
Powder layer (part thickness 30μm, content of inorganic powder)
35.0 g / m ² ) was formed, and a printing substrate and a label were obtained in the same manner as in Example 3 and attached to a glass / epoxy substrate.
It heat-processed at 300 degreeC for 1 hour.

In the above, the initial reflectance of the inorganic powder layer is as low as 65%, the inorganic powder layer is discolored by heat treatment, and the reflectance is 15%.
Fell.

In addition, the hardness of the inorganic powder layer is 50.17 kg / mm ² at a surface roughness of 0.1 μm, and the minimum hardness of a pencil that is scratched under a load of 1 kg is 7H. When a scratch was formed on the scratched portion, the metal was scraped off, and the scratched portion was colored by shavings of the metal.

[Brief description of drawings]

1 and 2 are sectional views of other embodiments, and FIG. 3 is an explanatory view of an example of a label base material. 1: Inorganic powder layer 11: Outer layer, 12: Inner layer 2: Heat resistant substrate 3: Heat resistant adhesive layer 4: Label substrate 5: Ink pattern

Front page continued (72) Inventor Kazuhiro Tajiri 1-2-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Hiroyoshi Tsuchiya 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Inside Denko Co., Ltd. (72) Inventor Hiroshi Nakashi 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (4)

(57) [Claims] 1. A flexible heat-resistant base material is provided on one side thereof with an inorganic powder layer which is shaped by an organic binder, an aromatic polyamide is used as the organic binder, and the content of the inorganic powder in the inorganic powder layer is adjusted. A heat-resistant printing substrate characterized by having a content of 30 g / m ² or more. 2. The inorganic powder layer is formed in a two-layer structure of an outer layer containing a small amount of an organic binder and an inner layer containing a large amount of the organic binder.
The heat-resistant printing substrate according to. 3. The hardness of the inorganic powder layer is HB to 6H.
The heat-resistant printing substrate according to. 4. A label formed by forming an ink pattern on the inorganic powder layer of the heat-resistant printing substrate according to claim 1.