JPH10305646A - Stamp face material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stamp face material which can maintain high image quality, by using a micro porous body of a threedimensionally continuous network frame obtained by excluding a low molecular material of a mixture of a copolymer having a hard block part of crystalline polyolefin and a soft block part and the low molecular material. SOLUTION: The stamp face material is a micro porous body of a three- dimensionally continuous network frame, particularly a three-dimensionally continuous network frame having an internal communication space 2, which is formed of a copolymer of a hard block part of crystalline polyolefin and a soft block part by removing a low molecular material held in a three- dimensional network frame 1. When the micro porous body of the structure is obtained by removing the low molecular material after the copolymer and a low molecular structural body are blended, it is important to mix both well. Since an end part never changes when the micro porous body is cut in a predetermined shape, the body can maintain high image quality and is suitable for use in stamps, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stamp face material, and more particularly to a stamp face material which is suitably used for stamps, especially stamps which form an image portion of an arbitrary shape on a stamp face by various means. .

[0002]

2. Description of the Related Art Conventionally, in order to produce a stamping device in which a rubber plate is fixed to a support, specialized techniques and equipment are required. For example, carving rubber in factories,
2. Description of the Related Art In general, a method of producing a rubber plate by forming a mold from the arranged type and casting a rubber plate, or forming a convex portion on a rubber surface by etching or the like has been generally performed. Therefore, when a general consumer creates an arbitrary stamp, it is necessary to ask an expert, and the desired stamp cannot be easily obtained. Therefore, recently, as a device that allows a general consumer to create a stamp by himself, an unprinted stamp surface attached to a support is processed by thermal means, so that an arbitrary image portion is formed on the stamp surface. Has been developed and put into practical use. According to the stamp plate making apparatus, a porous body made of syndiotactic 1,2-polybutadiene is used as a material for forming the stamp surface (hereinafter, sometimes referred to as a “print material”), and the surface of the stamp material is partially heated by thermal means. By forming an arbitrary image portion composed of a convex portion by melting the object, only the convex portion remains as an ink-permeable foam, and the image portion composed of the convex portion is impregnated with ink. It is possible to create a stamp for printing or printing.

However, foams used for stamps are required to have a very small cell diameter (50 μm or less) in order to improve image quality, but a conventional porous body requires a small cell diameter. Although it is possible, when cut into a predetermined shape, the cell at the end (cut portion) is crushed, and if a stamp surface is formed on this portion by a thermal means, the image quality will be significantly reduced, and an antiaging agent will be used. If not added, it has disadvantages such as deterioration of weather resistance.

[0004]

The present invention overcomes the drawbacks of the conventional foam used for such stamps, and can maintain high image quality when cut into a predetermined shape. An object of the present invention is to provide a stamp face material which is suitably used for stamps, especially stamps which form an image portion of an arbitrary shape on a stamp face by various means.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to develop a stamping material having excellent performance as described above, and as a result, the stamping material has been formed from a three-dimensional continuous network skeleton made of a specific material. It has been found that the object can be achieved by the microporous body. The present invention has been completed based on such findings. That is, the present invention comprises a three-dimensional continuous network skeleton obtained by removing a low molecular material from a mixture of a copolymer having a hard block portion and a soft block portion made of crystalline polyolefin and a low molecular material. The present invention provides a stamped surface material made of a microporous material.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The stamp surface material of the present invention is a microporous body having a three-dimensional continuous network skeleton structure, particularly a three-dimensional continuous network skeleton structure having an internal communication space. The network skeleton is formed of a copolymer having a hard block portion and a soft block portion made of crystalline polyolefin. The above copolymer,
Any material having a hard block portion and a soft block portion made of crystalline polyolefin may be used. Here, the type of the soft block portion and the arrangement of the repeating units in each block are not particularly limited, and may be any of graft, random, alternating, and block arrangements. On the other hand, the hard block portion is preferably made of crystalline polyolefin, particularly preferably made of crystalline polyethylene or polypropylene.

As such a copolymer, for example, (1) a crystalline polyethylene block (hard block portion)
(2) a copolymer having a crystalline polyethylene block (hard block portion) and a polyethylene / butylene block (soft block portion), (3) a crystalline polyethylene A copolymer having a block (hard block portion) and a polyvinyl acetate block (soft block portion); (4) a copolymer having a crystalline polypropylene block (hard block portion) and a polyethylene-propylene random block (soft block portion) Preferable examples include a polymer, and (5) a copolymer having a crystalline polyethylene block (hard block portion) and a block containing polypropylene (soft block portion).

In the copolymer (1), the hard block portion is made of a crystalline polyethylene block, and the soft block portion is made of a polybutene block. For example, "Esprene SPO.EBM" (Sumitomo Chemical Co., Ltd.) Product name). In the copolymer (2), the hard block portion is composed of a crystalline polyethylene block and the soft block portion is composed of a polyethylene / butylene block, and the ethylene-butadiene block copolymer is hydrogenated. Can be obtained by For example, a plurality of crystalline polyethylene blocks (for example, 3) are provided at an end of a soft block portion composed of a polyethylene / butylene block.
And Dynalon (trade name, manufactured by JSR Corporation). Further, in the copolymer (3), the hard block portion is made of a crystalline polyethylene block, and the soft block portion is made of a polyvinyl acetate block. For example, “Ultracene” (manufactured by Tosoh Corporation, product Name)
And "Evatate" (trade name, manufactured by Sumitomo Chemical Co., Ltd.). In the copolymer (4), the hard block portion is composed of a crystalline polypropylene block, and the soft block portion is composed of a polyethylene-propylene random block, that is, an EPR block. For example, “PER” (Tokuyama) (Product name). Finally, in the copolymer (5), the hard block portion is made of a crystalline polyethylene block, and the soft block portion is made of a block containing polypropylene. Here, as the block containing polypropylene of the soft block portion, for example, a soft polypropylene block, an EPR block, an EPD
M block and the like. The copolymer (5) can be obtained, for example, as “EP01” (trade name, manufactured by JSR).

These copolymers may be used alone or in combination of two or more. The three-dimensional continuous network skeleton composed of such a copolymer has a microporous structure as shown in the schematic diagram of FIG. That is, in FIG. 1, 1 is a three-dimensional continuous network skeleton, 2 is an internal communication space, and the microporous body having such a structure is
As will be described later, it is formed by removing the low molecular material held in the three-dimensional continuous network skeleton 1. In FIG. 1, the average diameter d of the three-dimensional continuous network skeleton 1 is 8 μm or less,
In particular, it is preferably in the range of 0.5 to 5 μm, and the average diameter D of the cell is preferably 200 μm or less, particularly preferably in the range of 1 to 50 μm. Further, the porosity is preferably at least 40%, particularly preferably in the range of 50 to 95%. Thereby, the resolution of printing and printing can be remarkably improved.

[0010] The microporous body having such a structure is formed by mixing the copolymer and a low-molecular material and then removing the low-molecular material. It is important to mix them under such conditions that a three-dimensional continuous network skeleton structure is formed. Specifically, it is desirable to use a high-speed stirrer such as a high-shear mixer to mix at a stirring speed of 300 rpm or more, preferably 500 rpm or more, more preferably 1000 rpm or more. When not stirring at high speed, for example, when mixing at low speed using a roll, a rotor type mixer, a cylinder type mixer, etc., obtain a uniform three-dimensional continuous network skeleton structure composed of the target copolymer. It is difficult. The mixing temperature is preferably in the range of 60 to 200 ° C., and the mixing time of about 1 to 120 minutes is sufficient. After the above mixing, crosslinking can be performed by adding a vulcanizing agent such as sulfur or an organic peroxide, or by irradiating an electron beam. In the present invention, the low-molecular material to be mixed with the copolymer is not particularly limited, and may be a solid or a liquid, and various organic materials can be used, but the number average molecular weight is less than 20,000, preferably 10,000 or less, More preferably, those having 5000 or less are advantageous. Examples of such a low-molecular material include the following materials.

Softener: Various rubber or resin softeners such as mineral oils, vegetable oils, and synthetic oils. Here, examples of the mineral oils include aromatic, naphthenic and paraffinic process oils. Vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil,
Palm oil, peanut oil, wood wax, pine oil, olive oil, and the like. Plasticizer: phthalic acid ester, phthalic acid mixed ester,
Various ester plasticizers such as aliphatic dibasic acid ester, glycol ester, fatty acid ester, phosphate ester, stearic acid ester, epoxy plasticizer, plasticizer for plastics or phthalate, adipate,
NBR plasticizers such as sebacate, phosphate, polyether and polyester.

Tackifier: Coumarone resin, Coumarone-
Various tackifiers (tack fire) such as indene resin, phenol terpene resin, petroleum hydrocarbon, and rosin derivative. Oligomer: Crown ether, fluorinated oligomer, polyisobutylene, xylene resin, chlorinated rubber, polyethylene wax, petroleum resin, rosin ester rubber, polyalkylene glycol diacrylate, liquid rubber (polybutadiene, styrene-butadiene rubber, butadiene-acrylonitrile rubber, poly) Various oligomers such as chloroprene rubber), silicone-based oligomers, and poly-α-olefins. Lubricants: hydrocarbon lubricants such as paraffin and wax,
Fatty acid lubricants such as higher fatty acids and oxy fatty acids, fatty acid amide lubricants such as fatty acid amides and alkylene bis fatty acid amides, ester lubricants such as fatty acid lower alcohol esters, fatty acid polyhydric alcohol esters and fatty acid polyglycol esters, aliphatic alcohols, Various lubricants such as alcoholic lubricants such as polyhydric alcohol, polyglycol and polyglycerin, metal soaps, and mixed lubricants.

In addition, latex, emulsion, liquid crystal, bituminous composition, clay, natural starch, sugar, inorganic silicone oil, phosphazene and the like are also suitable as low molecular weight materials. Animal oils such as cow oil, pork oil, horse oil, bird oil or fish oil: honey, fruit juice, dairy products such as chocolate or yogurt, hydrocarbons, halogenated hydrocarbons, alcohols, phenols, ethers -Based, acetal-based, ketone-based, fatty acid-based, ester-based, nitrogen compound-based, sulfur compound-based, and other organic solvents: or various medicinal ingredients, soil modifiers, fertilizers, petroleum,
Water, aqueous solution, etc. are suitable. These components may be used alone or in combination of two or more. These low-molecular materials are held between three-dimensional continuous network skeletons (particularly in internal communication spaces) composed of the above-mentioned copolymer. It is preferred to form a continuous network skeleton. When the amount of the copolymer constituting the three-dimensional continuous network skeleton is A and the low molecular weight material is B, the weight fraction of the copolymer [{A / (A + B)} × 100] is 30% or less. Especially 7
Preferably it is 25%.

The polymer network structure thus obtained has a structure in which the low-molecular material is held between three-dimensionally continuous network skeletons of the copolymer (particularly in the internal communication space). By removing the low-molecular material from the polymer network, a microporous body composed of a three-dimensional continuous network skeleton, which is the stamp surface material of the present invention, is obtained. In the stamp face material of the present invention, substantially all of the low-molecular material can be removed, but a part of the low-molecular material may be contained in the microporous body in order to reduce the hardness. In this case, the content of the low molecular weight material is 0 to 50% by weight.
Is particularly preferable, and a range of 0.5 to 30% by weight is particularly preferable. If the content of the low molecular weight material exceeds 50% by weight, when left on a resin such as an ABS resin or polystyrene, the resin may stick to these resins, and the hardness becomes too low to cause excessive melting during heating. May occur, making it impossible to make a plate precisely.

The method for removing the low molecular weight material is not particularly limited. For example, a method in which the low molecular weight material is dissolved and extracted using a suitable solvent and the remaining solvent is volatilized and dried is preferably used. Here, the solvent used is not particularly limited as long as the copolymer is insoluble or hardly soluble and the low molecular weight material is easily soluble.
Various things can be used. Preferred examples of such a solvent include organic solvents such as acetone and alcohol, and aqueous solvents such as water / diol and water / alcohol. As an operation when dissolving and extracting using these solvents, for example, a polymer network structure containing a low-molecular material is formed into small pieces or a thin film, and then immersed in the above-described solvent to extract the low-molecular material. Is preferred. The stamp surface material of the present invention thus obtained is suitably used as a stamp surface for forming an arbitrary image portion on the stamp surface by thermal means, and is usually used as a stamp material on a suitable support. By mounting, it forms a stamp face of stamps. In this case, usually, the stamp surface material of the present invention is formed in a sheet shape, punched out into an appropriate shape and size to form a stamping material, and mounted on a support to form stamps. In the stamp face material of the invention, roundness (sagging at the time of punching) does not occur along the ridge line of the surface into which the blade enters, and platemaking defects due to sagging do not occur.

The support on which the stamp material of the present invention is mounted is not particularly limited as long as it can surely support the stamp material from the back surface side, and various types are used. be able to. For example, the support may be of a type that supports and fixes the stamp face material with an adhesive or a pressure-sensitive adhesive, or may be a support that supports and fixes the stamp face material by mechanically sandwiching or pressing the stamp face material. The stamp surface material of the present invention is suitably used, in particular, for partially melting its surface by thermal means to form an arbitrary image portion composed of a convex portion. By forming an image portion composed of this convex portion, only the convex portion remains as a porous body that can transmit ink, and a printing surface for performing printing or printing by impregnating the image portion composed of this convex portion with ink is provided. It is formed. Here, the method for impregnating the image portion with the ink is not particularly limited. For example, a method of laminating another porous body or a foam body impregnated with the ink and supplying the ink from the porous body or the foam body Or a method of directly impregnating the ink. The thermal processing means for partially melting the stamped surface made of the stamped surface material of the present invention to form an arbitrary image portion on the stamped surface includes a heating element capable of heating and melting the stamped surface material. Any means can be used as long as it can control the heating element to melt the stamped surface into an arbitrary shape, and various means can be adopted. A known light or laser means such as a flash valve or a light emitting diode can be used. A known thermal means such as a thermal head can be used.

[0017]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Examples 1 to 4 Copolymers and low molecular weight materials of the types and amounts shown in Table 1 were mixed at a temperature of 180 ° C. and a rotation speed of 2500 using a high shear mixer.
After mixing under a condition of rpm to obtain a sheet-like polymer network structure, acetone (Example 1), ethanol (Example 2) or a water / alcohol solvent (Examples 3 and 4) is used as a solvent. Thus, a low-molecular material in the structure was removed to obtain a microporous body. The content of the low-molecular material in the microporous body and d and D of the cell skeleton were measured. The results are shown in Table 1.

[0018]

[Table 1]

[Note] (1) Kind of copolymer A: Copolymer consisting of crystalline polyethylene block and polyethylene / butene random block (Sumitomo Chemical Co., Ltd., trade name: Esplene SPO.EBM) B: Crystal Copolymer made of crystalline polyethylene block and polyethylene / butylene random block (manufactured by JSR Corporation, trade name: Dynaron CEBC type) C: Copolymer made of crystalline polyethylene block and polyethylene / vinyl acetate random block (Sumitomo Chemical Industries, Ltd.) D: Copolymer of crystalline polypropylene block and polyethylene / propylene random block (trade name: PER, manufactured by Tokuyama Corporation) (2) Types of low molecular weight materials i: Dioctyl phthalate / dioctyl Adipate mixture (weight ratio 20/80) B: Dibutyl phthalate / diethyl phthalate mixture (weight ratio 70/30) c: dibutyl phthalate / dioctyl phthalate mixture (weight ratio 5/95) (3) Molecular weight Polystyrene equivalent weight average measured by gel permeation chromatography (GPC) method. Molecular weight

Next, the microporous body was punched out into a predetermined shape by a Thomson mold to obtain a stamp face material, which was mounted on a plate making apparatus using a thermal head to make a stamp face.
Melting performance, weather resistance, and image quality of this material and a conventional porous body of syndiotactic 1,2-polybutadiene (melting point = 95 ° C.) were compared and studied according to the following methods. The results are shown in Table 2. (1) Melting performance When the surface of the stamp face material was heated and melted using a thermal head as a thermal means, it was visually observed whether or not the entire stamp face was uniformly melted, and evaluated according to the following criteria. ：: The entire stamp surface is extremely uniformly melted. Δ: The stamp surface is slightly unevenly melted. ×: Excessive melting is observed in a part of the stamp surface. (2) Weather Resistance After standing in an oven at 60 ° C. for 7 days, the state of the stamp surface was visually observed and evaluated according to the following criteria. ：: No change at all △: Slight change observed ×: Hardening is observed at the ridge of the surface where the blade enters during punching (3) Image quality The image quality immediately after the production of the stamp face material and after standing in a 60 ° C oven It was visually observed and evaluated according to the following criteria. ：: Extremely good image quality △: Slightly good image quality ×: Poor image quality at the ridge line on the surface where the blade enters during punching

[0021]

[Table 2]

[0022]

The stamp surface material of the present invention can maintain high image quality because its edges do not change when it is cut into a predetermined shape, and can maintain stamps, especially stamp surfaces by various means. It is suitably used for stamps that form an image portion having an arbitrary shape.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of the structure of a microporous body constituting a stamp face material of the present invention.

[Explanation of symbols]

 1 Three-dimensional continuous mesh skeleton 2 Internal communication space d Average diameter of skeleton 1 D Average diameter of cell

Claims (8)

[Claims] 1. A three-dimensional continuous network skeleton obtained by removing a low molecular material from a mixture of a copolymer having a hard block portion and a soft block portion made of crystalline polyolefin and a low molecular material. Stamp surface material made of microporous material. 2. The hard block portion made of crystalline polyolefin in the copolymer is a hard block portion made of crystalline polyethylene or polypropylene.
The stamp face material described. 3. The stamp face material according to claim 1, wherein the copolymer is a copolymer having a crystalline polyethylene block and a polybutene block. 4. The stamp face material according to claim 1, wherein the copolymer is a copolymer having a crystalline polyethylene block and a polyethylene / butylene block. 5. The stamp face material according to claim 1, wherein the copolymer is a copolymer having a crystalline polyethylene block and a polyvinyl acetate block. 6. The stamp face material according to claim 1, wherein the copolymer is a copolymer having a crystalline polypropylene block and a polyethylene-propylene random block. 7. The stamp face material according to claim 1, wherein the copolymer is a copolymer having a crystalline polyethylene block and a block containing polypropylene. 8. An average diameter d of the skeleton of the microporous body is 8 μm.
2. The stamp face material according to claim 1, wherein the average diameter D of the cell is 200 μm or less.