JPH06248577A - Mold release material for shaping and its production - Google Patents

Abstract

PURPOSE:To obtain a mold release material, excellent in shaping properties, shape retaining characteristics at high temperatures and repetitiveness by laminating a specific copolymer resin film subjected to embossing treatment processing to a support without being subjected to the embossing processing. CONSTITUTION:A copolymer resin film of polypropylene and one selected from alkenylsilanes and nonconjugated dienes as a polypropylene copolymer resin is subjected to thermal embossing treatment and then irradiated with electron rays (or a light irradiation method or thermal waves, etc.). A bonding resin (e.g. a resin curable by irradiation with ultraviolet or electron rays) is applied to one surface of the copolymer resin film in which the copolymer resin is cross-linked at >=20% get fraction measured by hot m-xylene extraction and a support without being subjected to embossing treatment (e.g. cast-coated paper, art paper or woodfree paper) is brought into close contact with the coated surface of the resin film to cure the resin with the ultraviolet rays, etc. Thereby, the objective mold release paper for shaping without losing the shape even by repetitive use is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cast paper, art paper, coated paper, lightly coated paper, paper such as high-quality paper, or a release material having a polyester resin film as a support. The present invention relates to a release material for mold making.

[0002]

2. Description of the Related Art A mold-releasing material is a synthetic leather, carbon fiber pre-prepared material, in which a mold-releasing layer made of polypropylene resin, silicone resin or alkyd resin is provided on a support such as high-quality paper or coated paper. Flooring,
It is used as a mold release material for casting urethane paste, vinyl chloride sol, etc. in the manufacturing process of marking films and the like.

The role of the release material used for producing synthetic leather is to hold the resin solution such as urethane paste until it is dried, and to release the dried resin film. In the case of casting, the surface of the release material is used. Since the shape is transferred, it also serves as a mold. Required properties of the mold release material are barrier properties that prevent the resin solution from seeping into the support, mold release properties that allow the resin film to be easily peeled off after drying, heat resistance during drying, and mold release materials can be used repeatedly. Because there are many,
Moderate tensile strength, tear strength, curl balance,
It has flexibility and scratch resistance so that the surface of the release material does not crack during embossing.

In the case of producing a transfer such as synthetic leather having a flat surface property (enamel, matte, etc.), coated paper or cast paper may be used as a support, and the top may be treated with a releasable resin. In the case of producing a transcription product with a mold, a laminate layer containing polypropylene resin as a main component is mainly used for the purpose of reproducibility of a particularly minute portion of the mold or prevention of cracking of the release material due to sharp unevenness. It is usually provided on the surface. Such a laminated layer made of polypropylene not only has some peelability by itself, but even when a release layer such as a silicone resin is provided thereon, its uniform coating property or reduction in the coating amount of the release agent is required. It is useful in a sense.
For example, when the resin forming the synthetic leather is urethane paste, the drying temperature is usually lower than the melting point of polypropylene, and thus polypropylene laminate is often used. However, in consideration of the productivity of synthetic leather, it is preferable that the drying temperature is high, and if the drying temperature is high, there is a dilemma that the embossing pattern tends to collapse.

[0005]

When a mold-releasing material having such a mold is prepared, a laminated base material using polypropylene has heat resistance for urethane paste, but when the mold-releasing material is repeatedly used at high temperature. In addition, the problem that the mold collapses, the problem that when paper is used for the support, the swelling due to moisture of the paper and the mold collapse causes the laminate base itself to lose its shape, and the low adhesiveness of polypropylene to paper etc. Of the polypropylene layer, or mixing of low-density polyethylene to cover the low adhesiveness of this polypropylene, or the introduction of an ethylene component during the polymerization of propylene reduces the heat resistance and deteriorates the mold retention. There was a problem such as. Furthermore, when embossing is applied to a polypropylene laminated base material with paper as a support, the entire base material, that is, the back surface of the paper also has irregularities, so that when it is wound, it cannot be firmly wound and the winding diameter is There is also a problem that it becomes large and it is difficult to control the tension while holding the mold. Therefore, the problems to be solved by the present invention are that the reproducibility of the molding is good, the high temperature can be used, the adhesiveness between the laminate layer and the support is good, and the mold does not lose its shape even after repeated use. To provide a mold release material.

[0006]

Means for Solving the Problems The inventors of the present invention have made earnest studies on means for solving the above problems, and have found the following inventions. That is, in the mold release material, the mold release material is obtained by laminating an embossed polypropylene copolymer film and a non-embossed support, and the polypropylene copolymer resin film is propylene and alkenylsilane or A copolymer with one or more compounds selected from non-conjugated dienes, and a light irradiation method, an electron beam irradiation method,
Heat m by one or more methods selected from heating methods
-The invention is a mold release material characterized by being crosslinked to have a xylene extraction gel fraction of 20% or more. It is possible to bond the embossed polypropylene copolymer resin film to a support which is not embossed by an adhesive resin polymerized by ultraviolet irradiation or electron beam irradiation.

The mold-releasing material of the present invention comprises one or more kinds selected from a step of embossing a polypropylene copolymer resin film and a method of irradiating the polypropylene copolymer resin film with a light irradiation method, an electron beam irradiation method or a heating method. Depending on the method, the heat m-xylene extraction gel fraction crosslinks to 20% or more, the step of applying an adhesive resin to at least one of the support or the embossed polypropylene copolymer resin film, and the embossed polypropylene copolymer It can be produced by combining the step of bringing the polymer resin film and the support into close contact with each other via the adhesive resin and the step of curing the adhesive resin by ultraviolet irradiation or electron beam irradiation if necessary.

As the polypropylene copolymer resin used in the present invention, a copolymer with an alkenylsilane mainly containing propylene or a copolymer with a non-conjugated diene mainly containing propylene, or from the viewpoint of heat resistance, It is a terpolymer of propylene, alkenylsilane, and non-conjugated diene. If necessary, ethylene may be introduced into these copolymerization components. Also in the polymerized form, any structure such as isotactic, syndiotactic and atactic may be used. These polypropylene copolymer resin films can be used by laminating them to a support by embossing or crosslinking the unstretched or stretched film. It is also possible to mix and use other polyolefin resins such as general polypropylene, polyethylene and polymethylpentene (TPX) at the time of film formation. There are no particular restrictions on the homopolymers, copolymers, terpolymers, etc. of general polypropylene used as a mixture with a polypropylene copolymer resin. These polypropylene copolymer resin films have many non-gel components at high temperature when left uncrosslinked (almost 100% are non-gel components when uncrosslinked), and have fluidity in the high temperature region near the melting point, Not suitable for use.

As a method of reducing the high temperature non-gel component of the polypropylene copolymer resin constituting the mold release material, a method of kneading a polyfunctional monomer and reacting by heating, and a method of kneading a polyfunctional monomer and a sensitizer are also used. The reaction is performed by light, the method in which light is irradiated in chlorine gas or acetylene gas to introduce a chloro group or vinyl group to react with a polyfunctional monomer, the method in which plasma discharge is performed in dilute acetylene gas, and the reaction is performed with ozone. A method of oxidizing and reacting with a polyfunctional monomer having an allyl group or an acryloyl group, a method of kneading a sensitizer such as benzophenone or N-methyl-2-benzoyl-β-naphthiazoline and irradiating light to react an unsaturated bond in the molecule, and light irradiation Alternatively, graft reaction of radicals generated by γ-ray or electron beam irradiation with monomers such as acrylic acid There can be many methods such as a method of causing it.

[0010] Polyethylene and the like are crosslinked by electron beam irradiation in terms of uniformity and easiness of reaction, but in the case of polypropylene, it is known that decomposition proceeds by electron beam irradiation. Simply irradiating the electron beam further lowers the heat resistance.

However, as shown by the present invention, as a polypropylene copolymer resin, a copolymer with alkenylsilane mainly containing propylene, a copolymer with non-conjugated diene mainly containing propylene, or a non-conjugated resin with propylene resin. When a copolymer of diene and alkenylsilane is used as a release layer, not only electron beam irradiation but also
It was revealed that the crosslinked structure can be removed by light irradiation and heat curing, and the release layer having the crosslinked structure of a certain level or more is very excellent as a mold release material.

The non-conjugated diene used as a copolymerization component in the present invention is, for example, 1,4-pentadiene, 1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,
5-hexadiene, 1,5-heptadiene, 6-methyl-1,5-heptadiene and the like, which are generally copolymerizable with propylene in the presence of a Ziegler catalyst. When copolymerized, one double bond remains in the side chain and has a crosslinking effect by the subsequent crosslinking treatment. The polymerization ratio of the non-conjugated diene is, when copolymerized with the propylene and ethylene components, within the range of 0.5 to 10 mol%. When the amount of the non-conjugated diene is less than this range, the crosslinking effect is not sufficient and the heat resistance is high. Also, there is a problem in high temperature type retention, and if it exceeds this range, uniform copolymerization becomes difficult, and the effect of improving releasability and crosslinkability does not become better than a certain limit, which is economically disadvantageous.

The alkenylsilane used as a copolymerization component in the present invention is, for example, vinylsilane, vinylmethylsilane, vinylethylsilane, vinylpropylsilane,
It is a vinylalkyl or vinyldialkylsilane compound such as vinyldimethylsilane, which is generally easily copolymerizable with an olefin compound in the presence of a Ziegler catalyst.
The polymerization ratio of the alkenylsilane is within the range of 0.03 to 5 mol% when copolymerized with the propylene and ethylene components, and if the amount of the alkenylsilane is less than this range, the crosslinking effect is not sufficient and the heat resistance and high temperature are high. There is a problem in mold retention, and if it exceeds this range, uniform copolymerization becomes difficult, and the effect of improving releasability and crosslinkability does not become better than a certain limit, which is economically disadvantageous.

In the release layer used in the present invention, a polypropylene copolymer resin is used as a main component, but an ethylene component is introduced in a form of copolymerizing with a propylene component, or a polypropylene copolymer resin is blended with a polypropylene copolymer resin component. It is possible to introduce a polyethylene component. However, from the viewpoint of heat resistance, if the ethylene component cannot be crosslinked, the mixing ratio will be a limited value.

In the polypropylene copolymer resin film used in the present invention, if necessary, pigments and dyes such as titanium oxide, barium sulfate and calcium carbonate, antioxidants, optical brighteners, antistatic agents and dispersants. Various additives such as a stabilizer, a release agent and the like can be appropriately combined and added.

The laminated resin used in the present invention preferably has a thermal m-xylene extraction gel fraction of 20% or more. The hot m-xylene extraction gel fraction referred to here is
The ratio of the gel content when the polypropylene copolymer resin was extracted for 2 hours with hot m-xylene at the boiling point is a value obtained by the following method. In the case of a thermal transfer image-receiving sheet, 1 g of polypropylene copolymer resin in the precoat layer is separated (A: polypropylene copolymer resin usage amount) and cut into several sheets, and then glass filtration having a standard maximum diameter of 16 to 40 μm A glass filter (Shibata Kagaku Kikai Kogyo Co., Ltd., G3.5 with a pore number), put it in a sufficient amount of boiling m-xylene with a glass filter, and shake for 2 hours to heat m-xylene. When a soluble component was extracted and then vacuum-dried, the amount of polypropylene copolymer resin remaining without being dissolved in hot m-xylene (B: remaining amount of polypropylene copolymer resin) was calculated by the following mathematical formula 1. It is a value.

[0017]

[Equation 1] Gel fraction (%) = 100 × B / A A: Amount of polypropylene copolymer resin used (g) B: Remaining amount of polypropylene copolymer resin (g)

As a matter of course, when the polypropylene copolymer resin contains an inorganic substance such as titanium oxide or zinc oxide, or a polymer other than the polypropylene copolymer, the weight is subtracted from the calculation. To do. Regardless of the type of polypropylene, heat m- when treated for 2 hours
The xylene-extracted gel fraction will be a value of 1% or less as long as it is measured without crosslinking.

When an electron beam is used for crosslinking the polypropylene copolymer resin film, the amount of the electron beam to be irradiated is preferably adjusted within the range of 0.1 to 50 Mrad in the absorbed dose to the polypropylene copolymer resin film. . If it is less than 0.1 Mrad, a sufficient irradiation effect cannot be obtained, and even if the electron beam irradiation amount is increased to more than 50 Mrad, the level of crosslinking and heat resistance of the polypropylene copolymer resin film hardly change. When kneading into a polypropylene copolymer resin film resin or reacting an electron beam curable release resin coated on a laminate, irradiation of several Mrad is sufficient.

In the present invention, the polypropylene copolymer resin film can be simultaneously crosslinked in the steps of crosslinking the polypropylene copolymer resin film and laminating the support. For example, when an embossed polypropylene copolymer resin film is attached to a support using an electron beam curable adhesive resin and the adhesive resin is cured by electron beam irradiation, the polypropylene copolymer resin film is crosslinked at the same time. Processing is also achieved. The same applies to the case where the heat treatment electron beam irradiation is performed when the crosslinking and the curing of the adhesive resin are performed by light (especially ultraviolet rays). As a matter of course, there is no problem in performing the cross-linking treatment of the polypropylene copolymer resin film and the bonding / bonding of the embossed polypropylene copolymer resin film and the support in separate steps.

Representative examples of the resin (referred to as a radiation curable resin) which can be cured by ultraviolet irradiation or electron beam irradiation used as an adhesive resin in the present invention include (1) aliphatic, alicyclic and aromatic (Meth) acrylates of aromatic and araliphatic polyhydric alcohols and polyalkylene glycols (2) Of polyhydric alcohols obtained by adding alkylene oxides to aliphatic, alicyclic, aromatic and araliphatic polyhydric alcohols Poly (meth) acrylate (3) Polyester poly (meth) acrylate (4) Polyurethane poly (meth) acrylate (5) Epoxy poly (meth) acrylate (6) Polyamide poly (meth) acrylate (7) Poly (meth) acryloyloxy Alkyl phosphate (8) Side chain of (meth) acryloyloxy group Vinyl- or diene-based compound having a terminal (9) Monofunctional (meth) acrylate, vinylpyrrolidone, (meth) acryloyl compound (10) Cyano compound having an ethylenically unsaturated bond (11) Mono having an ethylenically unsaturated bond Alternatively, polycarboxylic acids and their alkali metal salts, ammonium salts, amine salts, etc. (12) Ethylenically unsaturated (meth) acrylamides or alkyl-substituted (meth) acrylamides and their multimers (13) Vinyllactams and polyvinyllactam compounds ( 14) Polyether having ethylenically unsaturated bond and its ester (15) Ester of alcohol having ethylenically unsaturated bond (16) Polyalcohol having ethylenically unsaturated bond and its ester (17) Styrene, divinylbenzene, etc. Aromatic Compound Having One or More Ethylenically Unsaturated Bonds (18) Polyorganosiloxane Compound Having (meth) acryloyloxy Group in Side Chain or Terminal (19) Silicone Compound Having Ethylenically Unsaturated Bond (20) ) Multimers of the compounds described in (1) to (19) or modified oligoester (meth) acrylates

These may be used alone or in combination of two or more, or may be used by laminating. Further, different resins may be applied to the embossed polypropylene copolymer resin film side and the paper support side and bonded together.
In particular, on the embossed polypropylene copolymer resin film side, a low-viscosity resin is applied, and a high-viscosity resin is applied on the paper support side to adhere them, or a compound having a hydroxyl group on one side and an isocyanate on the other side. The method of applying and adhering a compound containing a is effective from the viewpoints of adhesiveness and prevention of loss of shape. Further, it can be applied without a solvent, can be applied by dissolving it in an organic solvent, or can be emulsified in water or an insoluble organic solvent and applied, dried and cured. Further, a method such as heating or ultraviolet irradiation can be used as preliminary curing before curing by electron beam irradiation. The radiation-curable adhesive resin preferably contains an acryloyl group and has a structure of at least one of an epoxy group, an isocyanate or a urethane bond from the viewpoint of adhesiveness.

As the adhesive resin used in the present invention, in addition to radiation curable resin, acrylic resin, natural and synthetic rubber, styrene / butadiene copolymer, polyvinyl acetate,
Polyvinyl chloride, polystyrene, methacrylic resin, polyfumarate, polycarbonate, polyimide, polysulfone, polyphenylene oxide, ABS resin, AS resin, furan resin, silicon resin, fluororesin, polyacetal, vinyl acetate / ethylene copolymer, starch, silicone compound , Glue, casein, polyvinyl alcohol, polyurethane, epoxy, alkyd, melamine, polyamide, saturated and unsaturated polyester, polyurea, phenolic resin, polyvinylidene chloride, polyacetal, celluloid, etc., alone or in solution, aqueous solution, emulsion Can be used in the form of.
As a method for setting these adhesive resins, any method such as heat drying, heat polymerization, hot melt, ultraviolet curing, electron beam curing may be used.

The coating amount of the adhesive resin is not limited, but is preferably in the range of 1 to 50 g / m ² .
If the coating amount is less than this range, the adhesiveness between the polypropylene copolymer resin and the support is lowered, and if it exceeds this range, not only does it not contribute to the improvement of the adhesiveness, but the adhesive efficiency is lowered and the adhesive strength is lowered. There is. Examples of the method for applying the adhesive resin of the present invention include a gravure roll and transfer roll coater, a bar coater, a roll coater, an air knife coater, a U comma coater, an AKKU coater, a smoothing coater, a micro gravure coater, an air knife coater, a reverse roll coater, and a reverse roll coater.
~ 7 multi-roll coater, blade coater, dip coater, bar coater, rod coater, kiss coater, gate roll coater, squeeze coater,
Any coater such as a falling curtain coater, a slide coater, a die coater may be used.

These adhesive resins may contain organic or inorganic pigments, organic dyes, and doses such as kaolin, calcined kaolin, talc, wax, diatomaceous earth, calcium carbonate, aluminum hydroxide, and hydroxide. Examples thereof include magnesium, magnesium carbonate, titanium oxide, barium carbonate, urea-formalin resin, plastic beads such as styrene, ultramarine blue, crystal violet, and leuco dye coloring material.

The photoinitiators used in the present invention, especially when using the ultraviolet curing method, include acetophenones such as di- and trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzyl dimethyl ketal and tetra. There are methyl thiuram monosulfides, thioxanthones, azo compounds, etc., and they are selected from the viewpoints of the type of polymerization reaction of the radiation curable resin, stability, suitability with an ultraviolet irradiation device, and the like. The amount of the photoinitiator used is usually O.V. for the radiation curable resin. It is in the range of 1 to 5%. Further, a storage stabilizer such as hydroquinone may be used in combination with the photoinitiator.

As the electron beam irradiation method, a scanning method, a broad beam method, a caten beam method, an ion plasma method or the like is adopted, and an accelerating voltage for irradiating the electron beam is preferably about 100 to 300 KV. Although the same treatment as electron beam irradiation can be performed using γ rays, the dose density is generally low, which is not preferable as a manufacturing method.
Further, when ultraviolet irradiation is used, a photoinitiator and, if necessary, a sensitizer can be mixed and used, but there is a limit in terms of penetrating power. As a light source when using ultraviolet rays, for example, low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp,
A xenon lamp and a tungsten lamp are preferably used.

During the electron beam irradiation, if the oxygen concentration is high, there is a danger of ozone generation, and radicals formed on the surface of the polypropylene copolymer resin film react with oxygen to form a peroxide. Replace with inert gas such as helium, carbon dioxide, etc.
It is preferable to irradiate in an atmosphere in which the amount is suppressed to 0 ppm or less, preferably 400 ppm or less.

In the polypropylene copolymer resin film or on the surface thereof, an acryloyl group is attached to a molecular end or a side chain,
Silicone resin (mainly polydialkylsiloxane) having a functional group selected from methacryloyl group, vinyl group, epoxy group, vinylamide group, hydrosilyl group, silanol group, diazo group, acetylene group, thiol group,
A release agent such as a fluorine-containing resin, an alkyd resin, an aminoalkyd resin, or a long-chain alkyl group-containing resin can be applied and fixed. The release agent may be applied or fixed before or after embossing. The release agent is applied in the form of emulsion type, solvent type, solventless type,
It can be applied by a mixed melt extrusion system or the like, and as a curing mechanism, a condensation type, addition type, crosslinking type, ring-opening polymerization type reaction or the like is possible.

In the present invention, the moldability after repeated use at a high temperature is maintained because the polypropylene copolymer resin film that has been modeled and crosslinked and the support are less likely to expand and contract due to heating, absorption and humidification. This is because they are adhered by resin. That is, when paper is used as the support and polypropylene is melt-extruded and then subjected to patterning, the paper is also subjected to the patterning process, but the support is repeatedly subjected to high temperature and room temperature, dehydration and moisture absorption. By repeating it, the patterning of paper gradually becomes easier. As the paper is relaxed, the irregularities of the melt-extruded polypropylene layer are also relaxed, and the mold is usually deformed. In the method of the present invention, since the support is not embossed, it is considered that the polypropylene copolymer resin layer does not lose its shape following the shape change of the support.

Further, the method of the present invention maintains the moldability after repeated use at high temperature because the adhesive resin exists between the support and the polypropylene copolymer resin film on which the pattern is formed, and the polypropylene copolymer is used. This is because the polypropylene copolymer resin layer is reinforced from the inside because the resin film is cured by irradiation along the mold of the resin film. In particular, the radiation-curable adhesive resin and the thermosetting adhesive resin do not plasticize due to heat, so it is considered that the polypropylene copolymer resin layer is prevented from losing its shape due to heat.

According to the method of the present invention, since the polypropylene copolymer resin film and the support are adhered to each other by the adhesive resin, the polypropylene copolymer resin film itself does not have a problem of adhesiveness. That is, while polypropylene and TPX have a releasability by themselves, the adhesiveness with a support is not good whether the support is paper, synthetic resin film or metal foil laminate. Therefore, ethylene is copolymerized or mixed and melted to improve the adhesiveness, but this method sacrifices heat resistance, so repeated useability, mold retention, high temperature usability, etc. make worse. In the method of the present invention, it is not necessary to use such a substance having a low melting point, and it is possible to use it repeatedly at high temperature without losing its shape.

In the present invention, in order to improve the adhesiveness and wettability between the polypropylene copolymer resin layer and the support, even if surface treatment such as corona treatment is applied to the surface of the polypropylene copolymer resin film or the support, You may perform surface treatments, such as a subcoat. Further, on the back surface of the mold release material of the present invention, a back coat layer such as anti-curl, anti-static or peeling layer can be provided, and the back coat layer can be an antistatic agent, a hydrophilic binder, a latex, a hardener. A film agent, a pigment, a surfactant, a pressure-sensitive adhesive, etc. can be appropriately combined and contained.

Regarding the molding process of the polypropylene copolymer resin film, general matched steel embossing,
Any embossing method such as steel / steel embossing, paper / steel embossing, rubber / steel embossing, planographic steel embossing, high pressure embossing, heat embossing can be used. When one side of the polypropylene copolymer resin film is subjected to a molding process, the back surface may be flat or may be molded.

The support used in the present invention includes plain paper, plain glossy paper, glassine paper, fine paper, art paper,
Coated paper, coated paper such as cast paper, synthetic resin film, synthetic paper, and a combination of metal foil and paper are used, but mainly wood pulp of softwood pulp, hardwood pulp, and mixed softwood pulp is used. Natural pulp paper as a component is advantageously used. The thickness of the base paper is not particularly limited, but a smooth one is preferable, and its basis weight is 30 g / m.
^{2 to} 300 g / m ² is preferable.

In the method of the present invention, the base paper containing natural pulp as a main component, which is advantageously used, may contain various polymer compounds and additives. For example, starch, starch derivatives (cationized starch, phosphate esterified starch, oxidized starch, etc.), polyacrylamide, polyvinyl alcohol, polyvinyl alcohol derivatives (complete saponification, partial saponification, carboxy modification, cation modification, and other various modifications). Polyvinyl alcohol), gelatin (alkali treatment, acid treatment, various modified gelatin), etc., dry paper strength enhancer, natural polymer polysaccharides such as star gum and alginic acid derivatives, higher fatty acid metal salts, rosin derivatives, dialkyl ketones, alkenyls or alkyls. Sizing agents such as succinic anhydride, epoxidized higher fatty acid amides, organic fluoro compounds, dialkylketene dimer emulsions, etc., wetting of polyamide polyamine epichlorohydrin resins, melamine resins, urea resins, epoxidized polyamide resins, etc. Paper strength enhancers, stabilizers, pigments, dyes, antioxidants, optical brighteners, various latexes, inorganic electrolytes (sodium chloride, sodium sulfate, sodium phosphate, calcium chloride, lithium chloride, magnesium chloride, magnesium sulfate, chloride) Barium, etc.), pH adjusters, fixing agents such as sulfuric acid bands and aluminum chloride, calcium carbonate, kaolin,
A filler such as talc and clay, and an additive such as an organic conductive agent may be appropriately combined and contained. These contents may be dispersed in the pulp slurry at the paper making stage, may be added at the tab size after paper making, and the solution may be applied by various coaters.

[0037]

In the mold release material of the present invention, since the polypropylene copolymer resin film is cross-linked and the phenomenon of relief of irregularities of the support does not occur, polypropylene copolymerization in a form following the shape change of the support The resin film layer does not lose its shape and can be used repeatedly at high temperatures. In addition, since the adhesive resin that is less likely to be deformed by heat is cured along the irregularities of the polypropylene copolymer resin film, the irregularities of the polypropylene copolymer resin layer are reinforced from the inside to prevent deformation due to heat. There is. The mold release material of the present invention does not need to be copolymerized with ethylene to improve the adhesiveness of the releasable polypropylene copolymer resin film, or does not need to be mixed and melted, so that it can be repeatedly used at high temperature without losing its shape. .

[0038]

The present invention will be described in detail below with reference to examples, but the contents of the present invention are not limited to the examples.

Example 1 A commercially available process paper base paper (manufactured by Mitsubishi Paper Mills, process paper base paper 125 g / m ² ) was used as a support for a release material. 30 μm
Unstretched polypropylene copolymer resin film (1 mol% 5-methyl-1,4-hexadiene copolymerized with propylene as a non-conjugated diene) with a thickness of 1 is heat-embossed with a metal / paper embossing roll and then irradiated with electron beam (accelerated). Voltage: 200KV, absorbed dose about 0.5Mra
d) is carried out and the gel fraction of the polypropylene copolymer resin is adjusted to 6
Adjusted to 0%. Then, a corona discharge treatment is performed, and 20 g / adhesive resin composition (7: 3 mixture of urethane acrylate, Aronix M1210, monofunctional acrylate, Aronix M113, manufactured by Toagosei Kagaku Kogyo Co., Ltd.) is applied to the back surface.
It was applied at m ^{2 and} was brought into close contact with the process paper base paper, and electron beam irradiation (electron curtain, manufactured by ESI) was performed at an acceleration voltage of 250 kv so that the absorbed dose was 3 Mrad to obtain a mold release material.

Example 2 A corona-treated PET film (thickness 125 μm, made of dia foil) was used as a support for the release material.
Uniaxially oriented polypropylene copolymer resin film with a thickness of 30 μm (5-methyl-as non-conjugated diene to propylene)
1,0-hexadiene (0.10 mol% of the whole) was irradiated with ultraviolet rays from a medium pressure mercury lamp to crosslink the polypropylene copolymer resin film. The polypropylene copolymer film after irradiation with ultraviolet rays had a thermal m-xylene extraction gel fraction of 20%. After heat embossing with the same metal / paper embossing roll as in Example 1, a resin containing isocyanate as an adhesive resin (DIC BEAM QA30 manufactured by Dainippon Ink and Chemicals, Inc.)
0) Use 10 g / m ² and bring it into close contact with the support, 250 k
Electron beam irradiation was performed at an accelerating voltage of v so that the absorbed dose was 3 Mrad to obtain a mold release material.

Example 3 The same process paper base paper as in Example 1 was used as the support for the release material. A biaxially stretched polypropylene copolymer resin film having a thickness of 30 μm (5-methyl-1,4-hexadiene as a non-conjugated diene in propylene is 0.05 mol% of the whole) is irradiated with ultraviolet rays by a medium-pressure mercury lamp to obtain a polypropylene copolymer. The polymerized resin film was crosslinked. The polypropylene copolymer resin film after irradiation with ultraviolet rays had a thermal m-xylene extraction gel fraction of 10%. Then, the same metal / paper embossing roll as in Example 1 was used for hot embossing. Then perform corona discharge treatment,
Adhesive resin (Epoxy / polyamide adhesive Araldite manufactured by Ciba-Geigy Co., Ltd.) is applied to the back surface at 20 g / m ² ,
The release resin was obtained by bringing it into close contact with the process base paper and curing the adhesive resin with a hot air dryer at 100 ° C.

Example 4 The same process paper base paper as in Example 1 was used as the support for the release material. Biaxially stretched polypropylene copolymer resin film with a thickness of 30 μm (a copolymer of propylene and vinylsilane, vinylsilane being 1 mol% of the whole) was subjected to electron beam irradiation (accelerating voltage: 200 KV, absorbed dose of about 5 Mrad) to obtain polypropylene. The gel fraction of the copolymer resin film was adjusted to 80%. Then, the same metal / paper embossing roll as in Example 1 was used for hot embossing. Then, apply corona discharge treatment, apply 20 g / m ² of adhesive resin (Epoxy / polyamide adhesive Araldite manufactured by Ciba-Geigy Co., Ltd.) on the back surface, and bring it into close contact with the base paper for the process paper. A mold release material was obtained by curing.

Example 5 Art paper having a basis weight of 125 g / m ² was used as a support for the release material. Biaxially stretched polypropylene copolymer resin film having a thickness of 40 μm (a copolymer of propylene and ethylene, and vinylsilane in a molar ratio of propylene:
Ethylene = 98: 2, vinylsilane (0.05 mol% of the total) was subjected to hot embossing by the same metal / paper embossing roll as in Example 1, and then crosslinked by ultraviolet irradiation with a medium pressure mercury lamp. The hot m-xylene extraction gel fraction of the crosslinked polypropylene copolymer resin film was 30%. Then perform corona discharge treatment,
Adhesive resin composition (including a 50:50 mixture of urethane acrylate UV3400 and Shin Nakamura Chemicals, epoxy acrylate NK ester EA800, manufactured by Toagosei Kagaku Kogyo Co., Ltd., containing 2% by weight of Ciba Geigy Irgacure 651 as a photoinitiator) on the back surface. It is applied at 20 g / m ² and brought into close contact with the process paper base paper, and a 120 w / cm high pressure mercury lamp 2
Curing was performed using a lamp to obtain a release material.

Comparative Example 1 As the base paper for the release material, the same commercially available process base paper as in Example 1 was used. After subjecting the surface to corona treatment, polypropylene resin was melt-extruded to a thickness of 30 μm for lamination. The hot m-xylene extraction gel fraction of this polypropylene resin laminate layer was 0%. The same metal / paper embossing roll as in Example 1 was used for hot embossing to obtain a mold release material.

Comparative Example 2 As a base paper for a release material, the same PET resin film as in Example 2 was used, the surface was corona treated, and polypropylene resin containing 10% by weight of ethylene was melt extruded to a thickness of 30 μm. And laminated. The hot m-xylene extraction gel fraction of this polypropylene resin laminate layer was 0%. The same metal / paper embossing roll as in Example 1 was used for hot embossing to obtain a mold release material.

The mold release materials obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were subjected to the following tests. The results are shown in Table 1.

[Mold storability] In each sample, a 2 cm square of the same pattern portion was analyzed by a three-dimensional roughness measuring device under the conditions of 500 point sampling in the X direction and 500 line sampling in the Y direction, and a ten-point average roughness SRz, The maximum height SRma and the maximum peak height SRp were obtained. Next, for each sample, urethane paste for synthetic leather (trade name Chris Bonn 6116S
L, manufactured by Dainippon Ink and Chemicals, Inc., containing 30% of methyl ethyl ketone as a solvent), dried at 140, then paste-coated again, heat-dried at 145 ° C. by overlaying with a urethane resin-impregnated base cloth, and release material. And separated to obtain synthetic leather. Using the used release material, the same synthetic leather was prepared 10 times to obtain a used release material. In each of the release materials after use, the same pattern portion as that measured before use was analyzed in the same manner by a three-dimensional roughness measuring device, and a ten-point average roughness SRz,
The maximum height SRma and the maximum peak height SRp were determined and expressed as a ratio (%) to the corresponding parameters of the three-dimensional surface roughness of the release material before use. The mold storability was expressed as the average value of the ratio of these three parameters. The higher this value, the better the mold storability.

[Adhesiveness] Synthetic leather was repeatedly prepared three times for each sample, and then the imprinted portion (release layer) and the substrate were peeled off to confirm the adhesiveness. When the release layer (polypropylene copolymer resin film layer) or the base material was broken, the adhesive property was good, and the release layer and the base material were poor.

[0049]

[Table 1]

Evaluation: Since the mold release materials prepared in the examples are prepared by adhering a polypropylene copolymer resin film which has been embossed in advance to a support using an adhesive resin, the mold release material can follow the shape change of the support. The polypropylene copolymer resin film layer does not lose its shape, and the embossed unevenness is reinforced from the inside, so that it can be used many times at high temperatures. Also, the adhesive strength between the support and the polypropylene copolymer resin film is high, and the repeatability is good.

[0051]

As is apparent from the above evaluation, the mold release material of the present invention is excellent in moldability, mold storability at high temperature use, and repeatability, and has great practical value.

Claims (3)

[Claims] 1. A mold-releasing material, wherein the mold-releasing material comprises a polypropylene copolymer film embossed and a non-embossed support bonded together via an adhesive resin. The resin film is made of a copolymer of propylene and one or more compounds selected from alkenylsilanes or non-conjugated dienes, and one or more methods selected from a light irradiation method, an electron beam irradiation method and a heating method. The mold releasing material for molding is characterized in that the thermal m-xylene extraction gel fraction is cross-linked by 20% or more. 2. An embossed polypropylene copolymer resin film is attached to a non-embossed support with an adhesive resin made of a radiation curable resin polymerized by ultraviolet irradiation or electron beam irradiation. The mold release material according to claim 1, wherein 3. A step of embossing a polypropylene copolymer resin film, and thermal m-xylene extraction of the polypropylene copolymer resin film by one or more methods selected from a light irradiation method, an electron beam irradiation method and a heating method. The step of crosslinking the gel fraction to 20% or more, the step of applying an adhesive resin to at least one of the support and the embossed polypropylene copolymer resin film, and the embossed polypropylene copolymer resin film and the support. A method for producing a mold release material, comprising a step of bringing the resin into close contact with an adhesive resin and a step of curing the adhesive resin by ultraviolet irradiation or electron beam irradiation if necessary.