JPH115250A - Sheet for vacuum press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a pattern elongation even at high temperature without bringing out blushing, crack or pattern elongation even in a low temperature mold at the time of vacuum pressing, by designing in a graph taking a stress at an ordinate axis and sheet temperature at an abscissa axis so as to become a specific number in a predetermined sheet temperature range, and regulating in orientation or resin mixture. SOLUTION: A surface sheet 2 made of an oriented clear film made of polyolefin resin is provided on one side surface of a base material sheet 5 formed of oriented colored film made of polyolefin resin via a primer layer 4 and pattern layer 3, and a decorative sheet 7 for vacuum press is formed. The sheet 7 is designed so that a stress [MPa] of 100% modulus is changed at a gradient of -0.3 to -0.6 in a sheet temperature range of 40 to 120 deg.C, and regulated by orientation or resin mixture. Here, the modulus is a stress of material at the time of giving specific elongation, also called 'a tensile stress' and is a value obtained by dividing the stress by a strain.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The place and application of the vacuum press decorative sheet of the present invention are described below. These surface-decorated members include decorative materials for building interiors such as walls, floors and ceilings, window frames, doors for system kitchens and furniture, surface decorative materials for fittings such as handrails, surface decorative materials for furniture, Weak electricity / O
It is used as an A equipment cabinet or as a surface decoration material for vehicle interior materials such as automobiles.

[0002]

2. Description of the Related Art A decorative sheet using no vinyl chloride resin has recently been proposed from the viewpoint of ecology. As such a decorative sheet, for example, a pattern ink layer, an adhesive layer, and a thermoplastic transparent elastomer film layer are sequentially laminated on the surface of a base sheet made of a polyolefin resin having a masking property, and embossing is performed simultaneously with the lamination. Embossed decorative sheet provided with a pattern (JP-A-6-79)
No. 830).

[0003] Further, a pattern ink layer is provided on a base sheet made of a polyolefin resin having a hiding property, and the polyolefin transparent resin is eluted and laminated, and at the same time an embossed recess is provided, and the embossed recess is filled with a coloring ink. There has been proposed a wiping decorative sheet (JP-A-6-79850).

[0004]

However, when vacuum pressing is performed using the doubling decorative sheet made of the unstretched olefin-based resin, the processing temperature range is narrow, and whitening, cracking, and local stress concentration occur at low temperature molding. However, there is a drawback that pattern elongation is easily caused by high temperature, and pattern elongation due to excessive softening is easily generated at a high temperature. The present invention is to solve the above-mentioned disadvantages of the prior art, even if vacuum pressing, because the processing temperature range is wide, even at low temperature molding,
It is an object of the present invention to provide a decorative sheet in which pattern elongation due to whitening, cracking, and concentration of local stress does not occur, and pattern elongation due to excessive softening does not occur even at a high temperature.

[0005]

Therefore, in order to improve the moldability in a vacuum press, the present invention provides a stress Y [MPa] of 100% modulus on the vertical axis and a sheet temperature X [°] on the horizontal axis.
C], the sheet temperature is changed from 40 ° C. to 1
It was designed so as to be Equation 1 within the range of 20 ° C. The method is adjusted by stretching, blending a resin, or the like.

[0006]

Y = AX + B where −0.6 ≦ A ≦ −0.3 12 ≦ B ≦ 72 40 ≦ X ≦ 120 Y ≧ 0 By doing so, uniform elongation molding was achieved in the vacuum press working. .

That is, the present invention provides: (1) a vacuum in which a stress [MPa] of 100% modulus changes with a slope of -0.3 to -0.6 within a range of a sheet temperature from 40 ° C. to 120 ° C. Press sheet. (2) A sheet for vacuum press, wherein the sheet is made of a polyolefin-based resin. (3) A sheet for a vacuum press, wherein the sheet is subjected to decorative processing. (4) A sheet for vacuum press at a sheet temperature of 40 ° C. or higher and having no yield point. It is. When the inclination is large, it becomes sensitive to a change in temperature, the width of the molding process becomes narrow, and molding defects are likely to occur.
When the inclination is small and the stress is small as a whole, the sheet becomes too soft to be easily decorated. When the stress is large, molding cannot be performed.

[0008] Here, the modulus is a stress of a material when a specific elongation is given, and is also referred to as a tensile stress. This is a value obtained by dividing stress by strain. The yield point is a general term for the upper yield point and the lower yield point generated during the course of the tensile test. The initial stress in a material that can be lower than the ultimate stress, but which causes an increase in strain without an increase in stress. Also called yield stress.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the decorative sheet for vacuum press 7 of the present invention is made of a polyolefin resin on one side of a base sheet 5 made of a polyolefin resin stretched colored film via a primer layer 4 and a picture layer 3. Is provided.

As the base sheet or top sheet, for example, a polyolefin resin film or sheet produced by melt extrusion and further stretched (hereinafter referred to as a sheet in the present invention includes a film)
Is used. The thickness is about 50 to 500 μm, more preferably 50 to 200 μm.

Here, as the olefin resin, polyethylene, ethylene / propylene copolymer, ethylene / propylene
Butene-1 copolymer, polypropylene, propylene / butene-1 copolymer, polybutene-1, butene-1 / propylene / ethylene / 3 terpolymer, butene-1 / hexene-1 / octene-1 / ternary Resins such as copolymers and polymethylpentene may be used alone or in combination of two or more.

In order to prevent whitening, an olefin thermoplastic elastomer which is a composite material comprising an elastomer and an olefin resin can be used. There are the following three types of olefin-based thermoplastic elastomers. That is, a type in which an elastomer as a soft segment and an olefin resin as a hard segment are simply blended. A crosslinked type in which an elastomer and an olefin resin are partially crosslinked to form a composite. A type in which an elastomer is crosslinked and dispersed in an olefin resin.

Specific examples are described below. Type: The olefin-based resin is the same as described above for the olefin-based resin. Examples of the elastomer include various rubbers, and examples of the rubber include a diene rubber, a hydrogenated diene rubber, and an olefin copolymer rubber. Among them, a hydrogenated diene rubber is preferable. The hydrogenated diene rubber is obtained by adding a hydrogen atom to at least a part of the double bond of the diene rubber molecule, and has a role of suppressing crystallization of the polyolefin resin and increasing flexibility and transparency. In general, when a diene rubber is added to an olefin resin, the weather resistance and heat resistance are lower than that of the olefin resin without the diene rubber due to the double bond of the diene rubber. Is saturated with hydrogen, so that the olefin-based resin has good weather resistance and heat resistance without deterioration. Examples of the diene rubber include isoprene rubber, butadiene rubber, butyl rubber, propylene / butadiene rubber, acrylonitrile / butadiene rubber, acrylonitrile / isoprene rubber, and styrene / butadiene rubber. The olefin-based copolymer rubber is an elastic copolymer obtained by adding at least one polyene copolymerizable with two or three or more olefins. As the olefin, ethylene, propylene, olefin, or the like is used. Is
1,4 hexadiene, cyclic dienes, norbornane and the like are used. Preferred olefin copolymer rubbers include, for example, elastic copolymers containing an olefin as a main component, such as ethylene-propylene copolymer rubber, ethylene-propylene non-conjugated diene rubber, and ethylene-butadiene copolymer rubber. For the purposes of the present invention, styrene
Butadiene rubber is preferred. As the amount of rubbers,
It is about 1 to 90 parts by weight based on 100 parts by weight of the olefin resin. If the amount is less than 1 part by weight, the elasticity, elongation, and impact resistance due to the addition of rubber are insufficient, and cracks and cracks are likely to occur during bending such as V-cutting and drawing. If the amount is more than 90 parts by weight, the elasticity and the elongation percentage become too large, and it is not preferable because the examination upon printing becomes poor.

As a type, for example, Japanese Patent Publication No. 53-2
No. 1021, JP-B-53-34210, JP-B-56-15741 and the like.

(Coloring) If necessary, a coloring agent comprising a pigment or a dye is added for coloring. Transparent coloring, opaque (concealing) coloring depending on the application. The color of the base sheet is generally opaque because it can cover the surface of the adherend. As a coloring agent, inorganic pigments such as titanium white, zinc white, red stalk, vermilion, ultramarine blue, cobalt blue, titanium yellow, carbon black, isoindolino, Hanzai yellow A, quinacridone, permanent red 4
R, organic pigments or dyes such as phthalocyanine blue,
Metal pigments such as aluminum and pearls, pearlescent pigments made of foil powder of titanium dioxide-coated mica, basic zinc carbonate and the like are used. Further, if necessary, an inorganic filler may be added, and calcium carbonate, barium sulfate, clay,
Powders such as talc, silica (silicon dioxide), and alumina (aluminum oxide) are exemplified.

(Flame retardant) Aluminum hydroxide, magnesium hydroxide, antimony trioxide and the like are used. The addition amount is about 10 to 100 parts by weight based on 100 parts by weight of the resin, depending on the desired flame retardant grade.

(Ultraviolet Absorber, Light Stabilizer) The ultraviolet absorber and light stabilizer are for imparting good weather resistance (light resistance) to the resin. The amount of each agent is usually about 0.01 to 0.15% by weight. Generally, it is preferable to use an ultraviolet absorber and a light stabilizer in combination. As the ultraviolet absorber, an organic substance such as benzotriazole, benzophenone, and salicylic acid ester, or an inorganic substance such as zinc oxide, cerium oxide, and titanium oxide having a diameter of 0.2 μm or less can be used. As the light stabilizer, a hindered amine radical scavenger such as bis- (2,2,6,6-tetramethyl-4-piperidinyl) sebacate and a radical scavenger such as a piperidine radical scavenger can be used.

Since the adhesive strength between the base sheet and the topsheet deteriorates with time due to ultraviolet rays, it is not sufficient to secure the initial adhesive strength as a decorative sheet during production. (Black panel 63 ° C.) In order to have sufficient adhesion strength as a decorative sheet even after irradiation, an ultraviolet absorber may be added to the surface resin layer. As a result of various studies, it is preferable to add a benzotriazole-based ultraviolet absorber at 0.1% by weight or more or a hindered amine-based radical scavenger at 0.1% by weight or more as a result of various studies.

(Heat Stabilizer) A heat stabilizer is used to further improve the prevention of deterioration such as thermal discoloration during thermal processing. Known heat stabilizers such as phenol, sulfite, phenylalkane, phosphite, and amine can be used. No. An olefin elastomer obtained by using a copolymer rubber as a soft segment, blending them uniformly, and mixing them. (B) monoolefin rubber / (A) olefin polymer = 50 / 50-90
/ 10 (weight ratio).

The base sheet or top sheet made of a polyolefin resin sheet is formed by blending the above materials with a conventional method such as a melt extrusion method from a T-die, if necessary, and stretching. can get.

"Explanation of a method of bonding the base sheet and the top sheet" The top sheet is made into a base sheet by lamination by hot melting or by an adhesive such as a two-component curable urethane resin or melt-extruded polyethylene. The resin is laminated on the resin, or the resin of the top sheet is melt-extruded (extrusion) coated on the base sheet, laminated, and bonded.

[Explanation of Adhesive Layer] When laminating the base sheet and the topsheet by dry lamination, 2
An adhesive used in ordinary dry lamination, such as a liquid-curable urethane resin, is used. When the base sheet and the topsheet are thermally bonded, a reactive hot melt adhesive is used. Further, although the adhesion strength is lowered, an isocyanate-based anchor coating agent (for example, a compound such as triresin isocyanate and hexamethylene diisocyanate) can be used. Usually thermoplastic inks can also be used.

[Explanation of Easy Adhesion Treatment] It is possible to print a pattern directly on the polyolefin resin sheet itself or to apply an adhesive, but it is also necessary to determine the adhesive force between the pattern and the adhesive and the polyolefin resin sheet. When it is necessary to further increase the adhesive strength between the resin and the adhesive, apply an easy-adhesion layer to the surface of the resin sheet or the surface of the resin sheet on which the pattern is printed, corona discharge treatment, plasma treatment, etc. Apply.

Acrylic, vinyl chloride-vinyl acetate copolymer, polyester, polyurethane, chlorinated polypropylene and chlorinated polyethylene are used as the easy-adhesion layer (also called a primer layer or an anchor layer).

Examples of acryl include poly (methyl meth) acrylate, poly (ethyl meth) acrylate, propyl poly (meth) acrylate, butyl poly (meth) acrylate, methyl (meth) acrylate / (meth) acrylate Butyl acrylate copolymer, ethyl (meth) acrylate / butyl (meth) acrylate copolymer, ethylene / methyl (meth) acrylate copolymer, styrene (meth) methyl acrylate copolymer, etc. ) Acrylic resin composed of a homopolymer or a copolymer containing an acrylate ester (however, (meth) acryl means acryl or methacryl, and the same applies hereinafter).

Polyurethane is mainly composed of a polyol (polyhydric alcohol), and isocyanate is used as a crosslinking agent (curing agent).
Polyurethane. The polyol has two or more hydroxyl groups in the molecule, and examples thereof include polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, and polyether polyol. As the isocyanate, a polyvalent isocyanate having two or more isocyanate groups in a molecule is used. For example, 24 tolylene diisocyanate, xylene diisocyanate, 44
Aromatic isocyanates such as diphenylmethane diisocyanate, or aliphatic isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated diphenylmethane diisocyanate are used.

"Explanation of decoration processing" A desired decoration processing is applied to the resin sheet. Examples of the decoration processing include coloring by kneading a coloring agent, forming a pattern composed of a picture or a metal layer, forming an uneven pattern by embossing (heating press), and hairline processing.

(Coloring) Same as (Coloring) in “Description of Olefin Resin”.

(Picture) As the picture printing, a pattern is formed by ink (or paint) using a known printing method such as gravure printing, offset printing, silk screen printing, and transfer printing from a transfer sheet. As the pattern, wood grain pattern,
There are a stone pattern, a leather pattern, a geometric figure, a character, a symbol, or a solid front face. The pattern is provided on the front surface, the back surface, the front and back surfaces, or between the layers of the sheet.

As the ink (or) paint, chlorinated polyolefins such as chlorinated polyethylene and chlorinated polypropylene, polyesters, polyurethanes, acrylics, vinyl acetate, vinyl chloride-vinyl acetate copolymers, cellulose resins, etc. are used as binders. And one kind or a mixture of two or more kinds. A material obtained by adding known pigments as described above to the above is used. When printing directly on a polyolefin resin, it is preferable in terms of adhesiveness of a chlorinated polyolefin or polyurethane as a binder, but if an easy-adhesion primer is appropriately selected and a layer is formed, it is sufficient to use another binder. Gives good adhesion. When an adhesive layer is not used, a urethane-based high-temperature reaction type (150
-250 ° C) are preferred.

(Metal layer) A metal such as aluminum or chromium is formed by vacuum evaporation or the like. The metal layer may be formed on the front surface, or may be formed in a pattern so as to obtain the above-described pattern. Is formed in a desired pattern, a metal is vapor-deposited on the front surface and then washed with water to remove the metal layer immediately above the removal layer together with a known method.

(Embossing) As embossing,
Heat and soften the olefin resin, pressurize with an embossing plate,
It is formed by shaping, cooling and fixing, and a known single-wafer or rotary embossing machine is used. As the uneven shape, wood grain conduit groove, stone board surface unevenness (granite open face etc.),
Fabric surface texture, satin finish, grain, hairline, line and groove, mirror, flat surface. Further, if necessary, the concave portions of the concavo-convex pattern can be filled with a coloring ink by a known wiping method (see Japanese Patent Publication No. 58-14312).

(Wiping process) A known wiping method is applied to a concave portion of an uneven pattern (see Japanese Patent Publication No. 58-14312).
Is filled with a coloring ink. For example, shellac,
Koval, dammar, rosin, rosin ester and other natural resins or modified resins thereof, nitrocellulose, acetylcellulose, ethylcellulose, cellulose derivatives such as benzylcellulose, phenolic resins, urea resins,
Phthalic acid resin, maleic acid resin, melamine resin,
Synthetic resins such as polyvinyl acetate resin, polyvinyl chloride resin, acrylic resin, polyvinyl alcohol, polyvinyl butyral, epoxy resin, silicone resin, polyester resin, polyamide resin, polyurethane resin, etc. A paint or ink obtained by using a rubber derivative or the like such as chlorinated rubber or synthetic rubber as a constituent material of a vehicle and adding a coloring agent, an extender such as precipitated barium sulfate, a plasticizer, or the like to the vehicle is used. When an acrylic sheet is used as the surface sheet, it is preferable to use an acrylic or urethane aqueous emulsion type transparent or transparent coloring ink.

The colored paint or ink is coated on the concave portion of the sheet surface with a roll coat or a knife coat and then scraped off with a doctor blade or wiping paper to remove the colored paint or ink coated on the convex portion of the sheet. It is necessary to adjust the viscosity of the coloring paint or the ink composition only in the concave portions, the number of rotations of the roll, the blade angle of the doctor, the thickness, the sheet speed, the speed of the wiping paper, the hardness of the rubber roll, and the like. The color tone of this colored paint or ink is
For example, in the case of a wood pattern, it is preferably the same or similar to a conduit, and in the case of a stone pattern, for example, it is preferably the same or similar to a crack.

"Post-processing and use of decorative sheet" (substrate to be laminated) As a use of the present invention, a surface decorative material is laminated on the surface of various members. Examples of adherends include metal plates such as iron and aluminum, wood veneers, wood plywood, wood plates such as wood fiber boards, glass plates, ceramic plates such as ceramics, plate materials such as cement plates such as ALC, polyvinyl chloride, and the like. A plate material such as a resin plate of a phenol resin or the like, or a three-dimensionally shaped article (molded product) made of the above-mentioned various materials is exemplified.

(Lamination method) As a method of laminating the above-mentioned various members, for example, a method of laminating a plate-like substrate by pressing with a pressure roller via an adhesive layer, Japanese Patent Publication No. 50-191
No. 32, etc., the decorative sheet is inserted between the male and female molds for injection molding with the transparent resin layer side facing the cavity side, the molds are closed, and the male gate is closed. Injection molding and injection of a molten resin, followed by cooling to form a resin molded article and simultaneously bond and laminate a decorative sheet on its surface, a so-called simultaneous injection molding lamination method, Japanese Patent Publication No. 56-47768.
As described in Japanese Patent Application Publication No. Sho 60-58014 and the like, a decorative sheet is placed on the surface of a molded article facing or placed with an adhesive layer interposed therebetween, and pressure is applied by vacuum suction from the molded article side. While supplying the decorative sheet by the difference through the adhesive layer, the decorative sheets are successively pressed and laminated on the plurality of side faces constituting the columnar body by different rollers in a plurality of directions, so-called wrapping. Processing method, actual public university 15-31
No. 122, JP-A-48-47972, etc., a decorative sheet is first laminated on a plate-like substrate via an adhesive layer, and then the plate-like substrate is on the side opposite to the decorative sheet. Cut a V-shaped or U-shaped groove reaching the interface between the decorative sheet and the plate-shaped substrate on the surface, and then applying an adhesive in the groove, and bending the groove There is a so-called V-cut or U-cut processing method for forming a box or a column.

[0037]

【Example】

Example 1 By stretching a sheet mainly composed of polypropylene produced by extrusion film formation with a T-die, a stress [MPa] having a 100% modulus was obtained at a sheet temperature of 40 ° C to 120 ° C. The adjustment was made so as to change with a slope of -0.3 to -0.6. In this way, a transparent film and a colored film made opaque by adding a pigment were produced. Next, the colored film is subjected to a corona treatment, and a two-component curable urethane ink (trade name: AFS, manufactured by Showa Ink Industries, Ltd.)
Is solid printed as a primer, and then vinyl chloride
An abstract pattern was printed with an ink composed of a vinyl acetate copolymer and an acrylic resin (trade name: Kasei X Showa Ink Industries). Using a urethane-based adhesive (trade name, Seika Bond E295, manufactured by Dainichi Seika), the printed pattern was bonded to the transparent film by a dry lamination method.

Next, a desired sheet was obtained by embossing the surface (on the transparent film) to provide a grain-like unevenness.
The sheet is applied by a vacuum press molding machine to a MDF substrate having a thickness of 18 mm and a corner portion R of 5 mm, which is coated with a two-part curable emulsion adhesive (4710 No-Tape Kogyo) by spraying. Temperature 100 ° C
After heating for 40 seconds, suction was applied at a pressure of 4.0 kg / cm ² , and the sheet was laminated on a substrate as shown in FIG. In the decorative plate as shown in FIG. 2 formed in this manner, the extended portions such as the corner portions 10 and the end portions 17 had a uniform pattern and were excellent in design.

COMPARATIVE EXAMPLE 1 A decorative sheet was produced in the same manner as in Example 1 using a film mainly composed of polypropylene produced by unstretched film formation (under the above conditions, an inclination of about 1.3). This decorative sheet was laminated on the same base material as in Example 1 by a vacuum press molding machine to produce a decorative plate. At the corners of the decorative plate, the sheet was unevenly stretched, the pattern was disturbed, and the design was not good.

[0040]

As described above, the decorative sheet for vacuum press of the present invention has a wide processing temperature range even when subjected to vacuum press processing, and therefore, even at low temperature molding, pattern elongation due to whitening, cracking, and concentration of local stress. This has the effect of preventing the occurrence of pattern swelling due to the above and preventing the occurrence of pattern elongation for excessive softening even at high temperatures. That is, since the molding is performed while maintaining a certain range of stress within the molding temperature range, there is an effect that the resin is uniformly stretched.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one example of a decorative sheet for vacuum press of the present invention.

FIG. 2 is a perspective view showing an example of a molded decorative board of the present invention.

FIG. 3 is an enlarged sectional view of an end of the molded decorative board of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Emboss 2 Clear film (surface sheet) 3 Pattern printing layer 4 Primer layer 5 Colored film (base sheet) 6 Primer layer 7 Decorative sheet for vacuum press 10 Corner (three-dimensional) (R = 5mm) 12 Adhesive 15 MDF Base material 17 Edge (R = 5mm) 20 Molded decorative board

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B41M 3/06 B41M 3/06 E // B29K 23:00

Claims (4)

[Claims] 1. A sheet having a 100% modulus stress [MPa] within a range of from 40 ° C. to 120 ° C.
Vacuum press sheet that changes with a slope of -0.6 from 3 2. The vacuum press sheet according to claim 1, wherein the sheet is made of a polyolefin resin. 3. The sheet for vacuum press according to claim 1, wherein the sheet is subjected to decorative processing. 4. The vacuum press sheet according to claim 1, wherein the sheet temperature is 40 ° C. or higher and the sheet has no yield point.