JPH03155942A - Plastic laminate - Google Patents

Abstract

PURPOSE:To obtain a plastic laminate excellent in heat dimensional stability, having high whiteness, low in specific gravity and excellent in abrasion resistance by forming a film support from a polyester film specific in its heat- shrinkage factor and specific gravity and mixing a non-compatible polymer with the polyester film in a dispersed state to specify the shape factor of the non-compatible polymer in the film. CONSTITUTION:A plastic laminate is formed by laminating a surface hard layer to a film support and the film support is composed of a polyester film wherein a heat-shrinkage factor at 150 deg.C is below 2% and specific gravity is 0.95 or less and a non-compatible polymer is dispersed in and mixed with the polyester film and the shape factor of the non-compatible polymer in the film is 1-4. The hue b-value calculated by a differential colorimeter of the film support is -3 or less. The surface hard layer is composed of an active ray curable monomer mixture consisting of at least one kind of a monomer having three or more (meth)acryloyloxy groups in its one molecule and at least one kind of a monomer having 1-2 ethylenic unsaturated double bonds in its one molecule.

Description

[Detailed description of the invention] [Industrial application field] The present invention has a low specific gravity with good thermal dimensional stability, high surface hardness,
The present invention relates to a plastic laminate that has excellent abrasion resistance and is rich in whiteness. More specifically, touch panels, decorations and displays attached to glass or metal plates, electronic whiteboards and whiteboards, paper substitutes such as cards, labels, stickers, delivery slips, image receiving paper for video printers, The present invention relates to a plastic laminate used for receiving paper for barcode printers, maps, etc.

[Prior Art] It is well known that a white polyester film can be obtained by adding a large amount of titanium dioxide, calcium carbonate, etc. to polyester. It is also well known to add polypropylene to polyester to obtain a white polyester film.

[Problem to be solved by the invention] However, films obtained by adding large amounts of inorganic substances such as titanium dioxide and calcium carbonate to polyester can be given whiteness, but cannot be made to have a low specific gravity, and the film itself becomes hard. , it gives a stiff feel, which may be a problem depending on the application.

In addition, when polypropylene is added, the hardness of the film itself is somewhat alleviated compared to when inorganic substances are added, but not only is the thermal dimensional stability poor, but it is also softer and more flexible than paper. It has the disadvantage that it is not only inferior in whiteness, but also inferior in whiteness.

In addition, the film surface has low surface hardness and lacks wear resistance, so it is easily damaged by contact with other hard objects, friction, scratches, etc., and the damage that occurs to the surface will reduce its commercial value. It may deteriorate significantly or become unusable in a short period of time.

The present invention solves these problems, has excellent thermal dimensional stability,
The purpose of the present invention is to provide a plastic laminate having high whiteness, low specific gravity, high surface hardness, and excellent wear resistance.

[Means for solving the problem] The present invention provides a film support (I) and a surface hardening layer (II).
), in which the film support (1) is a polyester film having a heat shrinkage rate of less than 2% at 150°C and a specific gravity of 0.95 or less, and is incompatible with the polyester film. The present invention relates to a plastic laminate in which polymers are dispersed and mixed, and the incompatible polymer has a shape factor of 1 to 4 in the film.

The specific gravity of the polyester film constituting the film support (I) in the present invention is 0.95 or less, preferably 0.95 or less.
90 or less, more preferably 0°80 or less. 0.
This is because if it is greater than 95, the film will not have a soft feel or flexibility.

Flexibility is necessary in order to be able to clearly transfer an image even when the pressure of a thermal recording head is reduced when the paper is used as an image-receiving paper for a video printer, for example.

Thermal dimensional stability is also important because the film does not deform even during heat-applying processes such as thermal transfer, printing, and drying. In particular, the heat shrinkage rate at 150°C is often important.

Polyester as used in the present invention is a polymer obtained by condensation polymerization from diol and dicarboxylic acid, and dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, adipic acid, and sepatic acid. Diols are typified by ethylene glycol, trimethylene glycol, tetramethylene glycol, cyclohexane dimetatool, and the like. Specifically, for example, polyethylene terephthalate, polytetramethylene terephthalate, polyethylene-p-oxybenzoate, poly-1,4
-cyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, and the like. In the case of the present invention, polyethylene terephthalate and polyethylene naphthalate are particularly preferred.

Of course, these polyesters may be homopolyesters or copolyesters, and examples of copolymerization components include diol components such as diethylene glycol, neopentyl glycol, and polyalkylene glycol, adipic acid, sebacic acid, and phthalic acid. , isophthalic acid, 26-naphthalene dicarboxylic acid, and 5-sodium sulfoisophthalic acid.

In addition, this polyester contains various known additives,
For example, antioxidants, antistatic agents, etc. may be added. As the polyester used in the present invention, polyethylene terephthalate is preferable. Polyethylene terephthalate film has excellent water resistance, durability, and chemical resistance.

Incompatible polymers include poly-3-methylbutene-1, poly-4-methylpentene-1, polyvinyl-1-butane, ], ]41ransupoly2,3-dimethylbutadiene, polyvinylcyclohexane, polystyrene, polymethylstyrene. , polydimethylstyrene, polyfluorostyrene, poly-2-methyl-4-fluorostyrene, polyvinyl-1-butyl ether, cellulose triacetate, cellulose tripropionate, polyvinyl fluoride, polychlorotrifluoroethylene, etc. It is a polymer with a melting point of 200°C or higher. In the case of the present invention, poly-4-methylpentene-1, cellulose triacetate, and modified products thereof are particularly preferred from the viewpoint of price, thermal stability, dispersibility with polyester, and the like. Of course, the melting point of the incompatible polymer is 200°C or higher,
Preferably 210°C or higher, more preferably 220°C
It is desirable that the temperature is above 200°C, and if the dispersion shape of the incompatible polymer in the polyester film is not spherical, it often takes a flat layered shape (also,
The melting point of the incompatible polymer is preferably 300°C or lower, preferably 280°C or lower, and more preferably 260°C or lower. This is because the incompatible polymer will not dissolve unless it is below the melt extrusion temperature of the polyester.

The amount of the incompatible polymer added is preferably 3 to 3.
0% by weight, more preferably 5 to 20% by weight. If the amount added is less than 3% by weight, it is not only difficult to obtain a polyester film of the present invention with a specific gravity of 0.95 or less, but also
It is difficult to produce a white polyester film with a whiteness of 80% or more. On the other hand, if the amount of the incompatible polymer added exceeds 30% by weight, the polyester film of the present invention not only has poor mechanical properties but also poor thermal dimensional stability, and This is because the shrinkage rate is 5% or more, which makes it thick.

Next, a specific gravity lowering agent is a compound that is added to polyester and has the effect of reducing the specific gravity, and only certain compounds have this effect.

For example, polyalkylene glycols such as polyethylene glycol, methoxypolyethylene glycol, polytetramethylene glycol, polypropylene glycol,
Ethylene oxide/propylene oxide copolymer,
Further examples include sodium dodecylbenzenesulfonate, sodium alkylsulfonate, glycerin monostearate, and tetrabutylphosphonium para-aminobenzenesulfonate. In the case of the film of the present invention, polyethylene glycol is particularly preferred.

By adding a specific gravity lowering agent, the specific gravity of the polyester film can be reduced by 0.1 g/cc or more. Furthermore, the addition of this specific gravity lowering agent not only improves the whiteness of the polyester film and smoothes the surface, but also improves the arm opening resistance and greatly improves the stretchability of the polyester. There is also. The amount of the specific gravity lowering agent added in the present invention is preferably 0.11 to 5% by weight, more preferably 0.5 to 3% by weight. If the amount added is less than 0.1% by weight, the polyester film will not have a low specific gravity and will not be soft, and the specific gravity of the polyester film will be 0.95 or less, preferably 0.95% or less.
90, more preferably 0.85 or less.

On the other hand, if the additive content exceeds 5% by weight, not only will the effect of lowering the specific gravity not be recognized, but the whiteness of the film will decrease,
This is because the b value becomes a large positive value.

Next, it is necessary that the incompatible polymer has a nearly spherical shape in the polyester film, that is, the shape factor must be in the range of 1-4. Even if an incompatible polymer is added to a polyester film, the film properties obtained depending on the shape of the incompatible polymer, especially the correlation between the film's specific gravity and cushioning ratio, thermal dimensional stability, surface roughness, whiteness, etc. A big difference arises. In other words, when the shape of the incompatible polymer is close to spherical, not only can the specific gravity be lowered compared to when it is dispersed in layers,
A film with high whiteness, high cushioning rate, and good thermal dimensional stability can be obtained. Dispersing in a shape close to spherical in this way depends strongly on the viscosity, compatibility parameter, melting point of the incompatible polymer added to the polyester, as well as the type and amount of the specific gravity lowering agent, so it is difficult to predict. That is very difficult. A shape close to spherical means that the ratio of the major axis to the minor axis of the incompatible polymer dispersed in the film is 1.
− to 4, preferably 1 to 2.

Of course, the resulting film must have low thermal dimensional stability to be used in applications where heat is applied, such as image-receiving paper for printers and the like. That is, the heat shrinkage rate at 150° C. in both the longitudinal and width directions must be less than 2%, preferably less than 1%. For this purpose as well, it is necessary to heat-treat the polyester film at a temperature of 20,000° C. or higher, preferably 220° C. or higher, and of course it may be subjected to a relaxing treatment.

Further, the whiteness of the polyester film is preferably 80% or more, preferably 90% or more.

Further, the color tone value determined by a color difference meter is preferably 13 or less, preferably 14 or less, and -20 or more.

The smaller the b value, the better the apparent whiteness of the film, giving it a high-quality image.

The color tone changes by adding the above-mentioned incompatible polymer, specific gravity lowering agent, etc., but a fluorescent whitening agent may be added if necessary. As an optical brightener, the product name “Ubitec” OB is used.
, MD (Ciba Geigy), "0B-1" (Eastman), etc.

In the polyester film of the present invention, fine particles such as calcium carbonate, amorphous zeolite particles, anatase-type titanium dioxide, calcium phosphate, silica, kaolin, talc, and clay may be used in combination. The amount of these added is 0.005 parts by weight per 100 parts by weight of the polyester composition.
It is preferable to set it as 25 parts by weight. In addition to such fine particles, fine particles precipitated by a reaction between a catalyst residue and a phosphorus compound in a polyester polycondensation reaction system can also be used. Examples of the precipitated fine particles include those consisting of calcium, lithium and phosphorus compounds, or those consisting of calcium, magnesium and phosphorus compounds, and the content of these particles in polyester is based on 100 parts by weight of polyester. 0.05~1
．． Preferably, it is 0 parts by weight.

Next, a method for producing the film support (I) of the present invention will be described, but the method is not limited to this example.

An extruder in which 4-methylpentene-1 polymer as an incompatible polymer and polyethylene glycol as a specific gravity lowering agent are mixed with polyethylene terephthalate, thoroughly mixed and dried, and heated to a temperature of 270 to 300°C. Supply to A. If necessary, TiO2,5i02,C
Polyethylene terephthalate containing inorganic additives such as aCO3 is supplied to extruder B by a conventional method, and
How the extruder B layer polymer comes to the image surface layer in the layer die B/
It may be laminated into three layers of A/B configuration.

This molten sheet is heated to a drum surface temperature of 10 to 60℃.
The unstretched film is tightly cooled and solidified by electrostatic force on a drum cooled to
Cool with rolls at 0°C.

Subsequently, the longitudinally stretched film is held at both ends with clips and introduced into a tenter, and is laterally stretched in a direction perpendicular to the longitudinal direction in an atmosphere heated to 90 to 140°C.

The stretching ratio is 2 to 5 times in both the length and width directions, and the area ratio (longitudinal stretch ratio x lateral stretch ratio) is preferably 6 to 20 times. If the area magnification is less than 6 times, the resulting film will have poor whiteness, while if it exceeds 20 times, it will tend to tear easily during stretching and the film formability will tend to be poor.

In order to impart flatness and dimensional stability to the biaxially stretched film, the film of the present invention is heat-set at 150 to 230°C in a tenter, cooled uniformly, cooled to room temperature, and rolled up. A support (I) is obtained.

The polyester film used in the present invention includes corona discharge treatment on the surface of the polyester film in contact with the surface hardening layer (II) in order to more firmly bond the polyester film layer and the surface hardening layer (II), urethane resin,
Anchor treatment may be performed using a known anchor treatment agent such as epoxy resin, acrylic resin, or polyester resin.

In particular, those coated with a reaction product of a vinyl copolymer containing a hydroxyl group and a partial ester group of phosphoric acid and a polyisocyanate compound (described in Japanese Patent Publication No. 58-35 5145), or acrylic on a polyester resin containing parent wood groups. The undercoat with a composition consisting of a copolymer grafted with a polyester compound and a crosslinking agent improves the adhesion between the surface hardening layer (II) and the polyester film layer, and improves heat and humidity resistance, boiling water resistance, etc. It is preferable as a film with excellent durability.

Furthermore, within the scope that does not impede the purpose of the present invention, a printed layer of designs and images may be provided between the polyester film layer and the hardened surface layer (II) and/or on the outermost layer of the hardened surface layer (II). It's okay.

Examples of the surface hardening layer (II) in the present invention include acrylic, urethane, melamine, organic silicates, silicone, and metal oxides. Silicone-based and acrylic-based are particularly preferred in terms of hardness, durability, etc.
Further, from the viewpoint of curability, flexibility, and productivity, acrylics, particularly actinic radiation-curable acrylics, are preferred.

The actinic radiation-curable acrylic system contains an acrylic oligomer and a reactive diluent as active radiation polymerization components, and may also contain a photoinitiator, a photosensitizer, and a modifier 6 as necessary. Acrylic oligomers include those in which reactive acrylic groups are bonded to an acrylic resin skeleton, as well as polyester acrylics, urethane acrylics, epoxy acrylics, and polyether acrylics, as well as rigid skeletons such as melamine and isocyanuric acid. Examples include, but are not limited to, those in which an acrylic group is bonded to. A reactive diluent is a medium for a coating agent that functions as a solvent in the coating process, and it itself has a group that reacts with monofunctional or polyfunctional acrylic oligomers, and is a copolymer component of the coating film. This is the result. In addition, especially in the case of crosslinking using ultraviolet rays, since the light energy is small, a photopolymerization initiator and a sensitizer are required to convert the light energy and promote initiation. Specific examples of these acrylic oligomers, reactive diluents, photopolymerization initiators, sensitizers, crosslinking devices, etc. can be found in "Crosslinking Agent Handbook" edited by Shinzo Yamashita and Tosuke Kaneko, published by Taiseisha 1981, p. 267. to pages 275 and 562 to 593
The pages may be used as a reference, but the reference is not limited thereto. As commercially available products, products such as Mitsubishi Rayon Co., Ltd., Fujikura Kasei Co., Ltd., Dainichiseika Co., Ltd., Dainippon Ink and Chemicals Co., Ltd., Toagosei Chemical Co., Ltd., and Nitto Kasei Co., Ltd. can be used as multifunctional acrylic UV-curable paints. but is not limited to these.

Among these, at least one of the monomers (A) having three or more (meth)acryloyloxy groups in one molecule is particularly preferred.
A surface hardening layer ( It)
is preferable because it has excellent hardness and hardenability as well as abrasion resistance and flexibility.

In the present invention, there are three or more (meth)acryloyloxy groups in one molecule (herein, (meth)acryloyloxy group is an abbreviation for acryloyloxy group and methacryloyloxy group, and the scope of claims and In the following explanation, △△△(meta)rororo is an abbreviation of △△△rororo and △△△metalororo.) One molecule of monomer (A) Examples include compounds in which three or more hydroxyl groups of a polyhydric alcohol have three or more alcoholic hydroxyl groups that are esterified with (meth)acrylic acid.

Specific examples include pentaerythritol tri(meth)acrylate, pentaerythritol I-lutetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tritaerythritol penta(meth)acrylate, dipentaerythritol hexa( Examples include meth)acrylate, trimethylolprobanth(meth)acrylate, and the like.

These monomers (A) may be used alone or in combination of two or more.

The proportion of these monomers (A) used is preferably 20 to 90% by weight, more preferably 30 to 80% by weight, based on the total amount of polymerizable monomers.

If the amount of monomer (A) is less than 20% by weight, a cured film with sufficient wear resistance cannot be obtained;
If it exceeds 0% by weight, shrinkage due to polymerization will be large;
This is not preferable because distortion remains in the cured film or the flexibility of the film decreases.

As the monomer (B) having 1 to 2 ethylenically unsaturated di- or double bonds in one molecule in the present invention, any conventional monomer having radical polymerization activity can be used.

Examples of the compound having two ethylenically unsaturated double bonds in the molecule include the following (meth)acrylates (a) to (f).

(a) (Meth)acrylic acid diesters of alkylene glycol having 2 to 12 carbon atoms: ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 14-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate (meth)acrylate, 16-hexanethiol di(meth)acrylate, etc. 90 (b) (meth)acrylate acid diesters of polyoxyalkylene glycol: diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, Tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, etc. (C) (meth)acrylic acid diesters of polyhydric alcohols: Penta Erythritol di(meth)acrylate, etc. (d) (meth)acrylic acid diesters of bisphenol A or ethylene oxide and propylene oxide adducts of bisphenol A hydride: 22-bis(4-acryloxyethoxyphenyl)propane, 2.2 '-bis(4-acryloxypropoxyphenyl)propane, etc. (e) A terminal isocyanate group-containing compound obtained by reacting in advance a diisocyanate compound with two or more alcoholic hydroxyl group-containing compounds, and further alcoholic hydroxyl group-containing (meth) Urethane (meth)acrylates having two or more (meth)acryloyloxy groups in the molecule obtained by reacting acrylates: (f) Acrylic acid or methacrylic acid in a compound having two or more epoxy groups in the molecule. Examples include epoxy (meth)acrylates having two or more (meth)acryloyloxy groups in the molecule obtained by reacting the following.

Compounds having one ethylenically unsaturated double bond in the molecule include methyl (meth)acrylate, ethyl (meth)acrylate, n- and i-propyl (meth)acrylate, n-, sec and t-butyl. (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate
Acrylate, methoxyethyl (meth)acrylate,
Ethoxyethyl (meth)acrylate, hydroxyethyl (meth)acrylate, polyethylene glycol mono (meth)acrylate, polypropylene glycol mono (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate,
N-hydroxyethyl (meth)acrylamide, N-vinylpyrrolidone, N-vinyl-3-methylpyrrolidone,
Examples include N-vinyl-5-methylpyrrolidone.

These monomers (B) may be used alone or in combination of two or more.

The proportion of these monomers (B) used is preferably 10 to 80% by weight, more preferably 20 to 70% by weight, based on the total amount of monomers.

If the amount of monomer (B) exceeds 80% by weight, it is not preferable because it is difficult to obtain a crosslinked cured coating having sufficient wear resistance. Further, if the amount is less than 10% by weight, the flexibility of the film and the adhesion to the base material will decrease, which is not preferable.

One method for curing the actinic radiation-curable composition of the present invention is to irradiate it with ultraviolet rays; in this case, it is desirable to add a photopolymerization initiator to the composition. Specific examples of photopolymerization initiators include acetophenone, 22-jethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4.4'-
Dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methylbenzoylform-1, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutyl Carbonyl compounds such as phenone, 2.2-dimethoxy-2-phenylacetophenone, and 1-hydroxycyclohexylphenyl ketone; sulfur such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, thioxanthone, 2-chloro4thioxanthone, and 2-methylthioxanthone; and peroxide compounds such as benzoyl peroxide and di-1-butyl peroxide. These photoinitiators may be used alone or
Two or more types may be used in combination. The amount of photopolymerization initiator used is 0.01 parts by weight per 100 parts by weight of the polymerizable monomer composition.
．． ~10 parts by weight is suitable. When electron beams or gamma rays are used as curing means, it is not necessarily necessary to add a polymerization initiator.

In order to prevent thermal polymerization during production and dark reaction during storage, the actinic radiation-curable composition used in the present invention contains hydroquinone,
Hydroquinone monomethyl ether, 2. ．． It is desirable to add a known thermal polymerization inhibitor such as 5-1-butylhydroquinone. The amount added is based on the total weight of the polymerizable compound.
0.005 to 0.05% by weight is preferred.

The actinic radiation-curable composition used in the present invention may contain an organic solvent for the purpose of improving workability during coating and controlling coating film thickness, within a range that does not impair the purpose of the present invention. can.

As the organic solvent, one having a boiling point of about 50° C. to 150° C. is easy to use from the viewpoint of workability during coating and drying properties before and after curing. Specific examples include alcohol solvents such as methanol, ethanol, and isopropyl alcohol;
Examples include acetate ester solvents such as methyl acetate and ethyl acetate, ketone solvents such as acetone and methyl ethyl ketone, aromatic solvents such as toluene, and cyclic ether solvents such as dioxane. These solvents can be used alone or in combination of two or more.

Various additives can be added to the actinic radiation-curable composition used in the present invention, as necessary, within a range that does not impair the purpose of the present invention. For example, antioxidants, light stabilizers, stabilizers such as ultraviolet absorbers, surfactants, leveling agents,
Antistatic agents, etc.

The actinic radiation-curable composition used in the present invention may contain gloss such as silicon oxide particles and organic fillers to the extent that does not impair the purpose of the present invention, for the purpose of reducing the brightness and clarity of reflected images from external light sources. An erasing agent can be added to the surface of the actinic radiation-curable layer using commonly known methods such as embossing,
It is also possible to provide unevenness by a sand mat method or the like.

Active radiation refers to electromagnetic waves such as ultraviolet rays, electron beams, and radiation that polymerize acrylic vinyl groups, and in practical terms, ultraviolet rays are preferred because they are simple. Although the electron beam method requires expensive equipment and requires operation under an inert gas, it is advantageous in that it does not require the inclusion of a photopolymerization initiator, photosensitizer, etc. in the coating layer.

The thickness of the surface hardening layer (II) is 0. The thickness is preferably 5 μm or more and 10 μm or less. More preferably, the thickness is 1 μm or more and 5 μm or less. If the thickness of the surface hardening layer is less than 0.5 μm, the surface hardness is insufficient and scratches occur easily, and if it exceeds 10 μm, the cured film tends to become brittle and harden when the laminate is bent. This is undesirable because it tends to cause cracks in the film.

Moreover, a printed layer such as a pattern or image 7 may be provided on the outermost layer of the surface hardening layer (II) within a range that does not impair the object of the present invention.

[Manufacturing method] The plastic laminate of the present invention is manufactured by coating and curing a surface hardening layer (If) on a flexible film support (1).

Application methods for the actinic radiation-curable composition of the present invention include brush coating, dip coating, knife coating, roll coating, spray coating, flow coating, and rotation coating (spinner, whaller, etc.).
Commonly used coating methods such as these can be easily applied. Each method has its own characteristics, and the coating method is appropriately selected depending on the required performance of the laminate or the intended use.

Examples of methods for curing the actinic radiation-curable composition of the present invention include methods of irradiating active energy rays such as ultraviolet rays, electron beams, and gamma rays.

Practically speaking, a method using ultraviolet irradiation is simple and preferable. Ultraviolet sources include ultraviolet fluorescent lamps, low-pressure mercury lamps,
There are high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, and carbon arc lamps.

[Applications] 8 The thus obtained plastic laminate of the present invention has a low density, is rich in whiteness, and has excellent surface hardness and abrasion resistance, so it can be used in a wide range of applications.

For details, see touch panels, decorations and displays attached to glass or metal plates, displays on electronic whiteboards and whiteboards, paper substitutes such as cards, labels, stickers, delivery slips, receiver paper for video printers, and barcodes. It can also be used for various surface protection materials such as printer paper, maps, etc., such as covers for calculators and meters. Also,
It can also be used as a coated metal plate for home appliances, office equipment, construction equipment, vehicles, steel furniture, etc. In particular, it has excellent design and image clarity, so it can be used for exterior members of home appliances, etc.

[Method for measuring physical properties and evaluating effects] The methods for evaluating physical property values and evaluating effects of the present invention are as follows.

(1) Surface roughness according to JIS B12O3-1976, cutoff 0
．． The center line average roughness Ra and the maximum roughness Rt were determined at a measurement length of 25 mm and a measurement length of 4 mm (μm).

(2) Average spherical diameter of voids A cross section cut in the machine direction or perpendicular direction of the film during the film forming process was examined using a scanning electron microscope at a magnification of 1.000 times to 500 times.
A photograph was taken at a magnification of 0 times, and at least 100 voids within the specified thickness range were subjected to an image analyzer to determine the distribution of diameters of circles corresponding to the area of the voids.

The volume average diameter of this distribution is defined as the average spherical equivalent diameter of the void.

(3) Specific gravity: 25% by carbon tetrachloride-n-hebutane density gradient tube
The value in °C was used.

(4) Optical density OD Layer the films to a thickness of around 150 μm,
Measurement is performed using an optical densitometer (manufactured by Macbeth Co., Ltd. TR927).

The thickness and optical density were plotted, and the optical density corresponding to a thickness of 150 μm was defined as the optical density equivalent to a thickness of 150 μm.

(5) Whiteness U manufactured by Shimadzu Corporation based on J I 5-L-1015
100% magnesium oxide white board using V-260
The whiteness (%) was determined by the following formula, where the reflectance at a wavelength of 450 nm was set as B (%) and the reflectance at a wavelength of 550 nm was set as G (%).

Whiteness (%) -4B-3G (6) Whiteness The surface color of the film was measured with a color difference meter Σ80 manufactured by Nippon Heavy Industries, Ltd., and judged based on the obtained L value, a value, and b value.

■ Shape factor Similar to finding the average diameter of voids, the shape of the incompatible polymer in the cross section of the film is measured using an image analyzer.
It is expressed as the ratio of the average length/breadth of 100 pieces.

(8) Abrasion resistance Steel wool #0O00 was rubbed against the surface of the polyester film layer or the hardened surface layer, and the degree of scratching was evaluated using the following criteria.

S3: Hardly any scratches occur even if strongly rubbed.

S2: If it is rubbed quite strongly, it will be slightly scratched.

1 Even mild friction can cause damage to S.

(9) Pencil hardness According to JIS K5400, various hardness pencils are 90
Apply it to the polyester film layer surface at an angle of 100° and load 1k.
It is expressed as the hardness of the pencil when a scratch occurs when scratched under g.

(G) Cross-cut on the adhesive cured layer (100 squares of 1mrrr)
"Cellophane Tape °" CT-24) made by Chiban ■ was pasted on the cellophane adhesive tape, and after the cellophane tape was peeled off by hand, the degree of peeling was observed and evaluated according to the following criteria.

A3: Good (peeling area less than 5%).

A2: Slightly inferior (Peeling area 5% or more and less than 20%).

A1: Poor (peeling area 20% or more).

(11) Heat and humidity resistance After conducting a heat and humidity test at 60°C and 90%RH using a constant temperature and humidity chamber (Davai Espec Platinum Humidor P II-I G type), changes in appearance such as cracking2 were observed. After observation, the cross-cut test described in (1) above was conducted in the same manner.

(After the 121 boiling water resistant laminate was immersed in boiling water for 1 hour, abnormalities in appearance such as the occurrence of cracks were observed, and the same cross-cut test as before was conducted.

(1 rise Glossiness Glossiness measuring device (Suga Test Instruments Digital variable angle gloss meter U
GV-4D) was used to measure the surface gloss at an incident angle of 60° according to JIs Z-8741.

[Example] The present invention will be described based on an example. However, the present invention is not limited to the following examples.

Note that parts and % in the examples mean parts by weight and % by weight, respectively.

Example 1 Polyethylene terephthalate (intrinsic viscosity [η] = 0.6
5), 88% by weight, poly-4-methyl pliers: z-1 (
Mitsui Petrochemical (m TP X-D 820) 'e
A raw material containing 10% by weight and 2% by weight of polyethylene glycol having a molecular weight of 4000 was supplied to extruder A, melted at 285° C. by a conventional method, and introduced into the center layer of a T-die three-layer composite die.

On the other hand, 90% by weight of the above polyethylene terephthalate,
A raw material to which 10% by weight of calcium carbonate (average particle size 0.8 μm) and 0.01% by weight of fluorescent brightener “0B-1” were added was supplied to extruder B, and heated at 285°C by a conventional method. The melted material was laminated on both surfaces of a T-die three-layer composite die, and the melted sheet was cooled and solidified in close contact with a cooling drum kept at a surface temperature of 25° C. using an electrostatic charge method. Subsequently, the cast sheet was stretched 3.5 times in the longitudinal direction using a group of rolls heated to 98°C according to a conventional method, and then cooled to 25°C. Further, the stretched film was introduced into a tenter, stretched 3.2 times in the width direction in an atmosphere heated to 125°C, and heat-set at 225°C to obtain a film with a thickness of 100 μm. The thickness of the film was 5 μm for the surface layer and 90 μm for the center layer.

The physical properties of the obtained film include a specific gravity of 0.77 and a whiteness of 4-
05%, tone value 93, a value -1,0, b value -4,3,
Optical density 1.1-1 Heat shrinkage rate 0. 7%, width direction 0.2%, surface roughness Ra 0 .

21 μm, Rt 1-. 85. The dispersion shape is spherical, the shape coefficient is 1.0, the film has excellent thermal dimensional stability, and is a low specific gravity polyester film with high whiteness.

Next, 70 parts by weight of dipentaerythritol hexaacrylate, 3 parts by weight of N-vinylpyrrolidone,
0 parts by weight, 1-hydroxycyclohexylphenyl ketone (Ciba Geigy “fRUG A CU R,E” 1
．． 84) A composition obtained by stirring and mixing 4 parts by weight was uniformly coated using a bar coater so that the film thickness after curing was 311 m. This was cured under a high-pressure mercury lamp (manufactured by Toshiba) having an intensity of 80 W/cm set at a height of 12 cm from the coated surface at a speed of 3 m/min to obtain a laminate.

The surface of this laminate is smooth and has an abrasion resistance of S3 and a pencil hardness of 3.
H. The cross-cut cellophane tape peeling test was ranked A3.

Example 2 Specific gravity lowering agent polyethylene glycol used in Example 1 (
The amount of PEG) added was 0. A film with a thickness of 100 μmη was obtained in the same manner as in Example 1 except that the amount was 8 parts by weight.

The physical properties of the obtained film include a specific gravity of 0.82 and a heat shrinkage rate of 0.82 in the longitudinal direction. 9%, width direction 0.2%, color tone value -4,
1. It is a film with a shape factor of 1.2, low specific gravity, and excellent thermal dimensional stability.

The actinic radiation-curable coating composition used in Example 1- was applied onto this support film and cured in the same manner to obtain a laminate.

The surface of this laminate is smooth and has an abrasion resistance of S3 and a pencil hardness of 3.
I■: The cross-cut cellophane tape peeling test was ranked A3.

Example 3 Polyethylene terephthalate (intrinsic viscosity [η]-O, 6
5), 10% by weight of poly-4-methylpentene-1 (Mitsui Petrochemicals TI) 5 6 , melted at 285°C by a conventional method, and introduced into the center layer of a T-die three-layer composite die.

On the other hand, 90% by weight of the above polyethylene terephthalate,
10% by weight of calcium carbonate (average particle size 0.8 μm)
Added 0.01% by weight of fluorescent brightener "0B-1'"
The added raw materials are fed to extruder B, and heated at 285° using a conventional method.
The melted sheet was melted at C and laminated on the image surface layer of a T-die three-layer composite die, and the melted sheet was cooled and solidified in close contact with a cooling drum kept at a surface temperature of 25°C by an electrostatic charge method. Subsequently, the cast sheet was stretched 3.5 times in the longitudinal direction using a roll group heated to 98°C according to a conventional method, and then cooled to 25°C.

Next, a water-dispersible polyester copolymer grafted with acrylic, "Pess Resin" 604G (manufactured by Takamatsu Yushi ■), was diluted with water, and a melamine-based crosslinking agent "Nikaratsuku" MW-12LF (( 4 parts by weight of silica sol (manufactured by Catalyst Kasei Kogyo ■) with an average particle size of 0.10 μm were added as a lubricant to 1-00 parts by weight of resin solid content.
A coating agent containing 0.5 parts by weight per 00 parts by weight to give a concentration of 3.0% by weight was applied to one side of the above-mentioned axially stretched film using a metering bar, and the coated layer was dried for 10 minutes.
Stretched 3.5 times in the transverse direction at 0°C, and heat-treated at 220°C for 5 seconds while relaxing 3% in the transverse direction, to obtain a laminated polyester film with a thickness of 100 μm on which a modified layer of 0.1 μm was laminated. .

60 parts of pentaerythritol triacrylate, 2.2'-bis(4-
10 parts of acryloxyjethoxyphenyl)propane, N
- Film thickness after curing using a bar coater with a composition obtained by stirring and mixing 30 parts of vinylpyrrolidone, 4 parts of 1-hydroxycyclohexylphenyl ketone, 90 parts of toluene, 70 parts of butyl acetate, and 70 parts of isopropyl alcohol. is 3
It was applied uniformly to a thickness of μm. This was dried for 80 degrees for 18 seconds, and then cured at a speed of 5 m/min under high pressure water with an intensity of 80 W/cm set at a height of 1'2 cm from the coated surface in an N2 atmosphere. A laminate was obtained.

The surface of this laminate is smooth and has an abrasion resistance of S3 and a pencil hardness of 3.
H. Cross-cut cellophane tape peeling test ranks A3, heat and humidity resistance ranks A3, boiling water resistance ranks A.
It was 3.

Example 4 Using a support film that was undercoated with a hydrophilic group-containing polyester resin grafted with acrylic in the same manner as in Example 3, 70 parts by weight of dipentaerythritol hexaacrylate and 30 parts by weight of N-vinylpyrrolidone were applied on the undercoated surface. Department,
5 parts by weight of 1-hydroxycyclohexyl phenyl ketone, 3 parts by weight of silica powder (manufactured by Degussa, 0K-412, average particle size 4 μm), 70 parts by weight of butanol, 8 parts by weight of toluene.
A composition prepared by stirring and mixing 0 parts by weight was uniformly coated using a bar coater so that the film thickness after curing would be 3 μm. 80
After drying at ℃ for 30 seconds, a laminate was obtained by passing under a high-pressure mercury lamp having an intensity of 80 W/an set at a height of 12 cm from the coated surface at a speed of 3 m/min. The obtained laminate has abrasion resistance of S3, pencil hardness of 3H, cross-cut cellophane tape peeling test rank of A3, heat and humidity resistance of rank A3, boiling water resistance of rank A3, and surface gloss of 4.
It was 0.

Comparative Example 1 The abrasion resistance of only the support film obtained in Example 1 was S
1, scratches occur on the entire surface and the surface hardness is low.

As described above, if a surface hardening layer is not applied, a plastic laminate with excellent wear resistance and surface hardness cannot be obtained.

[Effects of the present invention] The present invention has heat shrinkage rate and specific gravity within a specific range,
By providing the surface hardening layer (II) on the film support (I) in which the shape of the incompatible polymer dispersed in polyester is close to spherical, the following effects can be obtained.

1. Despite having a small specific gravity of 0.95 or less, a film with excellent thermal dimensional stability and high whiteness can be obtained.

902, high whiteness and small toning value can be obtained, giving a high-class image.

3. A laminate with high whiteness and excellent surface hardness and abrasion resistance can be obtained.

Claims (6)

[Claims] (1) In a plastic laminate in which the film support (I) and the surface hardening layer (II) are laminated, the film support (I) has a heat shrinkage rate of less than 2% at 150°C and a specific gravity of 0.95. The following polyester film, wherein an incompatible polymer is dispersed and mixed in the polyester film, and the shape factor of the incompatible polymer in the film is 1.
4. A plastic laminate characterized in that it is 4. (2) The surface hardening layer (II) contains at least one monomer (A) having three or more (meth)acryloyloxy groups in one molecule and one to two ethylenic groups in one molecule. The plastic laminate according to claim 1, which is an actinic radiation-curable monomer mixture comprising at least one monomer (B) having an unsaturated double bond. (3) A claim (
The plastic laminate described in 1) or (2). (4) The incompatible polymer of the film support (I) is
Claims (1) to (3) characterized in that the polymer is a polymer with a melting point of 200°C or higher selected from methylbutene polymer, methylpentene polymer, styrene polymer, fluorine polymer, cellulose acetate, and cellulose propionate polymer. The plastic laminate described in any of the above. (5) Claim (I) characterized in that the film support (I) is obtained by incorporating a specific gravity lowering agent into polyester.
The plastic laminate according to any one of 1) to (4). (6) The specific gravity lowering agent in the film support (I) is selected from polyalkylene glycol, ethylene oxide/propylene oxide copolymer, alkylbenzene sulfonate, alkyl sulfonate, and modified products thereof. The plastic laminate according to claim 5, which is a plastic laminate.