JPH07157521A - Resin composition curable by actinic energy radiation, its cured product and production of cured product - Google Patents

Abstract

PURPOSE:To obtain a resin composition curable by actinic energy radiation, having excellent luster, stain resistance and solvent resistance, exhibiting high processability to enable the post-processing such as bending, drawing and deforming and suitable for the precoating of metals, plastics, etc., and for glass coating and to obtain a cured product of the composition and to provide a process for the production of the cured product. CONSTITUTION:This resin composition curable with actinic energy radiation contains at least two kinds of resin components consisting of (A) a high-density crosslinkable component and (B) a low-density crosslinkable component. The ratio of the high-density crosslinkable component A in the resin component of the surface layer of the cured resin is higher than the compositional ratio (A)/(B) of the resin composition before curing and the cured resin composition has a gradient component structure continuously decreasing the compositional ratio (A)/(B) of the high-density crosslinkable component A from the cured surface in the direction of depth. The invention also relates to a cured material having a gradient component structure and a process for producing the cured material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a high-density cross-linking component present on the surface of a cured resin in an amount exceeding the composition ratio of the high-density cross-linking component of the resin composition before curing. By having a component gradient structure in which the content ratio of the components is continuously reduced, excellent active energy having properties that were conventionally considered to be contradictory to the stain resistance of the surface of the cured product and the processability of the cured product itself. The present invention relates to a linear curable resin composition, a cured product, and a method for producing the cured product.

The resin composition of the present invention has a workability such that after curing, the cured product can be subjected to processing such as bending, stretching, and deformation, and the active energy ray curing is excellent in stain resistance of the cured surface. A mold resin composition, the cured product, and a method for producing a cured product are provided.

More specifically, after painting, bending, stretching,
For applications such as deformation, metal such as pre-coated metal, coating of plastics such as PET, vinyl chloride, ABS, PP, polycarbonate, nylon, etc., building materials, lamination, surface adhesive film for molded products, etc. , A coating material such as paper, a binder resin for magnetic recording materials such as video tapes and floppy disks that require flexibility, or surface contamination, scratch resistance, and shock absorption. Glass for building materials,
It can be widely used as a coating material for preventing glass from scattering, such as glass for automobiles and bottles.

[0004]

2. Description of the Related Art In recent years, a so-called post is used for manufacturing household electric appliances, interior / exterior building materials, office supplies, vehicles, etc. for the purpose of pollution-free, labor-saving, and process-saving. There is an increasing demand for a pre-coat paint which avoids a coat, is basically coated and cured before being processed, and is then subjected to various processes to obtain a desired shape.

Examples of the object to be coated include aluminum, iron,
Metal plates such as copper and various alloys, and various plastic materials such as polyester, vinyl chloride, and polycarbonate.Precoat paints for such processing are required in addition to improving the design and protecting the surface. It cannot be used as a pre-coat paint unless it has the workability mentioned above.

That is, the workability means that the coating film must have an elongation corresponding to the processing to be applied in order to bend or deform the coating plate. Therefore, the coating film needs to have an appropriate cross-linking density and glass transition temperature as a cured structure factor corresponding to the elongation. Generally, the larger the crosslink density, the larger the elastic modulus, but
Elongation decreases. The glass transition temperature is basically
The lower the value, the more flexible and the higher the elongation, but the lower the elastic modulus and the lower the strength of the cured product.

In addition to the above-mentioned elongation, the precoat paint is required to have both stain resistance and hardness on the surface of the coated article, and various resin compositions have been studied so far. For example, as a precoated steel sheet, as a resin composition that is generally used, a combination of a high molecular polyester resin and a melamine resin, the high molecular polyester has a good elongation, self-condensation of the melamine resin By cross-linking, it is intended to improve hardness and stain resistance.

Further, in a two-pack type urethane resin composition composed of a polyol and a polyisocyanate, an attempt has been made to improve the stain resistance and hardness by ensuring that the polyol component ensures the elongation of the coating film and the isocyanate increases the crosslink density. ing. Further, from the viewpoint of shortening the curing time and saving energy, studies are underway to use an active energy ray curing system such as an ultraviolet ray or an electron beam.

On the other hand, the component gradient structure referred to in the present invention is basically that the concentration of a specific component in a multi-component system changes in a specific direction (depth direction). , Some have been reported. For example, color material, 64
Vol. (12), pp. 720-786, Ikijima et al., Thermosetting system based on polyester-melamine system, Polymer Collection 44, No. On pages 1, 9-14 (January 1987), an example of a study on surface segregation of amino-alkyd cured resin coating film of Tazuru et al. Is reported.

Miki et al., Converter Tech, 1991.
/ 1, 1 page or Convertec, 1990/8,
On page 1, we report changes in the interfacial composition of fluororesin and acrylic resin due to solvent casting. See also Michelea
l B. Clark, Jr. Et al., Macromole
cules 1991, 24, 799-805, reports the analysis of their crystallinity, molecular weight and surface structure in the system of vinyl chloride and polyepsiloncaprolactone as high molecular weight homopolymers.

However, these are those in which a specific component is concentrated and oriented at the air interface or the substrate interface in a multi-component polymer blend or a thermosetting system, and the reaction with the active energy ray as in the present invention. None of the systems reported that specific components were concentrated or oriented.

The resin composition described in the present invention is basically an actinic radiation curable acrylate resin composition, and such a polyurethane acrylate and polyester acrylate resin composition. As a known example of the above, for example, a polyester urethane acrylate using an alicyclic dicarboxylic acid described in JP-B-4-31714,
A coated article having high weather resistance is disclosed in a combination system of non-aromatic acrylate.

In Japanese Patent Publication No. 2-7346, a polyurethane diacrylate having a specific molecular weight, a polyester diacrylate having a specific molecular weight, and a multi-component system such as a monovinyl compound are useful as an adhesive. A further composition,
In Japanese Unexamined Patent Publication (Kokai) No. 2-219811, various oligomers including ester acrylates and urethane acrylates or a mixture thereof are further cured with ultraviolet rays for the bottom surface of a vehicle such as a sealant containing acrylic ester. Mold resin compositions are disclosed.

However, these do not disclose a specific acrylate resin composition that forms the component gradient structure of the present invention, and by forming the component gradient structure by active energy ray curing, excellent precoat coating is achieved. It was not described or suggested that the product could be manufactured.

That is, in the precoat coating with the conventional resin composition, there is a limit to the compatibility of processability and stain resistance, no matter how the mixing ratio of them is examined. It has stain resistance, chemical resistance, etc.,
In addition, it was quite difficult to produce a pre-coated sheet which can withstand high workability of the cured product, for example, 180 degree bending (0T).

That is, the stain resistance correlates with the crosslink density of the surface. The higher the crosslink density is, the better the stain resistance is. However, when the crosslink density is high, the elongation of the cured product decreases. ,
There is a drawback in that there is a great limitation in processing because the coating film is broken and cracks are generated when it is forcibly deformed or processed because it cannot be freely deformed.

[0017]

The problem to be solved by the present invention is to have excellent gloss, stain resistance and solvent resistance,
In addition, since it has flexibility, it has high processability that can be subjected to post processing such as bending, stretching, and deformation, and is suitable for precoat coating and glass coating of metal, plastic, etc., active energy ray curable resin composition, curing Stuff,
Another object is to provide a method for producing the cured product.

[0018]

DISCLOSURE OF THE INVENTION As a result of intensive investigations, the present inventors have focused their attention on the problems to be solved by the invention as described above, and as a result, have found that the active energy ray curable type having a specific composition is used. By using a resin composition and further performing a heat treatment before curing the resin composition, a non-uniform structure in the depth direction of the cured coating film, that is, a high-density crosslinking component in the depth direction from the surface of the cured resin is obtained. The present invention has been completed by finding that a cured product having the component gradient structure of 1) is formed and that the above-mentioned problems can be solved by the cured product.

That is, the present invention provides a high-density crosslinking component (A).
And at least two resin components of the low-density cross-linking component (B), the high-density cross-linking component (A) in the resin component on the cured resin surface after curing, before curing The composition ratio (A) / (B) of the high-density cross-linking component (A), which is present in excess of the composition ratio of (A) / (B), decreases continuously from the cured resin surface in the depth direction. On the contrary, the active energy ray curable resin composition forms a component gradient structure in which the composition ratio of the low-density crosslinking component (B) continuously increases.

More specifically, the high-density crosslinking component (A) of the active energy ray-curable resin composition of the present invention is a resin component composed of a reactive resin having a trifunctional or more crosslinkable functional group, and has a low content. Density crosslinking component (B) is 1.0 mmol / g
It is a reactive resin component having the following reactivity.

More specifically, the active energy ray-curable resin in which the high-density crosslinking component (A) and the low-density crosslinking component (B) of the active energy ray-curable resin composition of the present invention are acrylate resins. An active energy ray curable resin composition which is a composition, in particular, the high-density crosslinking component (A) is a polyester acrylate, and the low-density crosslinking component (B) is a polyurethane acrylate. is there.

The active energy ray-curable resin composition for forming a component gradient structure in which the high-density crosslinking component (A) is a polyester acrylate and the low-density crosslinking component (B) is a polyurethane acrylate is also included in the present invention. included.

More specifically, the high-density crosslinking component (A) is
An active energy ray curable resin composition which is a polyfunctional acrylate having a trifunctional or higher functional group and has a molecular weight of 500 or less per acryloyl group, and a high-density crosslinking component (A) is a cyclic ester. Formed by reacting a compound, (meth) acrylic acid, and a trifunctional or higher functional polyol,
The present invention also includes an active energy ray curable resin composition which is a polyester acrylate having at least 3 or more functional groups.

In the present invention, the high-density crosslinking component (A) is
A cyclic acrylate compound having a molecular weight of 800 to 3000, and particularly a cyclic ester compound forming the high-density cross-linking component (A) is ε-caprolactone. A trifunctional or higher functional polyol constituting the density crosslinking component (A) is dipentaerythritol, which is an active energy ray curable resin composition.

The low-density crosslinking component (B) of the active energy ray-curable resin composition of the present invention is a linear polyurethane acrylate having a molecular weight of 3,000 to 30,000. More specifically, the low-density crosslinking component (B) is a linear polyurethane acrylate. -Like polyurethane acrylate is a polyurethane acrylate in which 4,4'-dicyclohexylmethane diisocyanate as an isocyanate component and polyester polyol and / or polycarbonate polyol as a polyol component are essential components. It is an energy ray curable resin composition.

The active energy ray-curable resin composition of the present invention comprises 9/1 to 1/9 of the above-mentioned high-density crosslinking component (A) and low-density crosslinking component (B) as essential constituent components.
It is an active energy ray-curable resin composition contained in a ratio of 9.

In the present invention, the active energy ray-curable resin composition of the present invention described above is applied to an object and then heated to 50 ° C.
The depth from the surface of the curable resin is characterized by curing the curable resin composition by irradiation with active energy rays after heat treatment at a temperature not lower than the decomposition temperature of the active energy ray curable resin composition. It includes a method for producing a cured product of an active energy ray resin having a component gradient structure of a curing component in the direction.

In the method for producing a cured product of active energy rays according to the present invention, the surface temperature of the coating film is controlled to 4 at the time of irradiation with energy rays.
A method for producing a cured product of active energy ray resin having a gradient structure of components, which is maintained at a temperature of 0 ° C. or higher and a temperature not higher than the decomposition temperature of the active energy ray curable resin composition, and active energy ray irradiation is inactive. Active energy having a gradient structure characterized by being performed in a gas atmosphere
It also includes a method for producing a cured wire resin.

More specifically, it is a method for producing a cured product of an active energy ray resin having a component gradient structure in which the active energy ray is an ultraviolet ray or an electron beam, and particularly when the active energy ray is an ultraviolet ray. Also includes a method for producing a cured product of active energy ray resin having a component gradient structure, which is characterized in that the active energy ray irradiation is carried out in an inert gas atmosphere.

The present invention further comprises a high-density crosslinking component (A),
By using at least two resin components of the low-density cross-linking component (B) as essential constituents, high-density cross-linking from the surface of the cured product to a depth of 100 angstrom by the measurement method by X-ray photoelectron spectroscopy (ESCA). The component (A) is present in excess of the composition ratio (A) / (B) of the resin composition before curing, and the crosslink density on the surface of the cured product is higher than the crosslink density inside the cured product.
It is a resin cured product having a component gradient structure cured by an active energy ray.

The present invention further comprises a high-density crosslinking component (A),
Infrared total reflection absorption spectrum (ATR)
-IR), the high-density crosslinking component (A) is present at a depth of 3 microns from the surface of the cured product in excess of the composition ratio (A) / (B) of the resin composition before curing. , A resin cured product having a component gradient structure cured by an active energy ray.

More specifically, the present invention uses at least two resin components, a high-density cross-linking component (A) and a low-density cross-linking component (B), as essential constituent components, and uses X-ray photoelectron spectroscopy (ES).
CA), the content ratio (A) / (B) of the high-density cross-linking component (A) and the low-density cross-linking component (B) at a depth of 100 angstroms from the surface of the cured product was measured before curing. Of the resin composition of (A) / (B), and at a depth of 100 angstroms from the surface of the cured product,
The composition ratio of (A) / (B) is from the composition ratio of (A) / (B) at a depth of 3 microns from the surface of the cured product by the measurement method by infrared total reflection absorption spectrum (ATR-IR). It also includes a resin cured product having a component gradient structure that is cured by an active energy ray, which is characterized by a high value.

Further, the present invention is characterized in that the surface of the cured product produced by the above-mentioned production method has stain resistance and solvent resistance, and the elongation at break of the cured product is 80% or more. It also includes a resin cured product that is cured by an active energy ray having a component gradient structure. The present invention will be described in more detail below.

The present invention basically comprises a high-density crosslinking component (A).
And a composition comprising the low-density cross-linking component (B) is heat-treated at a temperature of 50 ° C. or higher and a decomposition temperature of the active energy ray-curable resin composition or lower, prior to curing,
It causes the migration and reorientation of the components in the composition, a component gradient structure is formed in the depth direction of the coating film, the high-density cross-linking component is concentrated at the air interface in the coating film, and this is converted into active energy rays. By curing by curing, the surface has a high cross-linking density and good surface properties, and inside the hardened product there are many low-density cross-linking components. To obtain a cured product.

According to the present invention, the crosslink density inside the cured product is determined by the compounding ratio of the initially designed high density crosslink component and the low density crosslink component, and the crosslink density having sufficient processability, that is, the coating density. As a result of maintaining the processability of the entire cured product at a cross-linking density much lower than that of the film surface, it has a coating surface with excellent hardness, but has excellent processability, which is a property contrary to the conventionally known technology. A cured product will be obtained.

In order for the surface of the cured product to have satisfactory performances such as stain resistance and solvent resistance, the high density crosslinking component is present in the resin composition constituting the surface of the cured product in an amount of 60% or more. In other words, in other words, the high-density cross-linking component (A) in the resin component on the cured resin surface after curing is (A) /
Composition ratio of (B), for example, (A) / (B) = 25/7
A high-density crosslinking component (A) composition ratio of more than 5, for example,
(A) / (B) = 30/70 to 100/0 must be present.

The high-density crosslinking component (A) is a reactive resin having a trifunctional or higher functional crosslinkable functional group. More specifically, the high-density crosslinking component (A) is trifunctional or higher and has a thickness of 2 mm.
It is a reactive resin having a crosslinkable functional group having a reactivity of ol / g or more. More specifically, a polyfunctional polyester acrylate compound is preferable, and for example, a polyester acrylate compound having a molecular weight of 500 or less per (meth) acryloyl group and having a trifunctional or higher functional group number is preferable. Has excellent physical properties.

Specific examples of the resin composition forming the component gradient structure include a polyester acrylate having a trifunctional or higher functional group as the high-density crosslinking component (A) and a polyurethane acrylate as the low-density crosslinking component (B). The composition to be used is preferable, and this system has a high concentration of polyester acrylate at the air interface due to thermal stimulation, which is cured by irradiation with active energy rays, so that the surface has a high cross-linking density and stain resistance. Excellent layer is formed,
In addition, a soft cured product is obtained inside the cured product.

The polyester acrylate as the high-density cross-linking component (A) referred to here is a component of a cyclic ester compound, a trifunctional or higher functional polyol compound, and (meth) acrylic acid as essential components, for esterification or transesterification. The compounds obtained by the reaction preferably contain at least 3 or more (meth) acrylate groups, more preferably about 6 and the molecular weight thereof is preferably in the range of 800 to 3000.

When the number of functional groups in the high-density cross-linking component (A) is 3 or less, the cross-linking density when cured is small and the desired properties such as stain resistance are difficult to be exhibited. The molecular weight is 800
If it is lower, it becomes difficult to form the component gradient structure. On the other hand, if the molecular weight exceeds 3,000, the compatibility with the linear polyurethane acrylate becomes poor and it becomes difficult to handle the composition.

The cyclic ester compound referred to here is
γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, substituted ε-caprolactone, D-glucono-1,4-lactone, 1,10-phenanthrenecarbolactone, 4-pentene-5-olide, 12 -Lactones such as dodecanolide.

The substituted ε-caprolactone referred to herein is various ε-monoalkylcaprolactones in which the alkyl group has 1 to 12 carbon atoms,
For example, from monosubstituted alkyl lactones such as ε-methylcaprolactone, ε-ethylcaprolactone, ε-propylcaprolactone and ε-dodecylcaprolactone,
Two to three alkyl-substituted ones can be used. As the cyclic ester compound used in the present invention, ε-caprolactone is particularly preferably used.

Examples of the trifunctional or higher functional polyol compound mentioned here include trimethylolethane, trimethylolpropane, ditrimethylolethane, ditrimethylolpropane, guar, glycerin, diglycerol, 3-methylpentane-1,3,3. 5-triol, pentaerythritol, dipentaerythritol, tripentaerythritol, 2,2,6,6, -tetramethylcyclohexanol-1, tris2-hydroxyethylisocyanurate, mannitol, sorbitol , Inosito-
, Glucose, etc. As the trifunctional or higher functional polyol compound used in the present invention, dipentaerythritol is particularly preferably used.

Further, a cyclic ester compound, a trifunctional or higher functional polyol compound and (meth) acrylic acid are esterified,
When reacting such as transesterification, a polyol compound other than the above, or a carboxyl group-containing compound or an ester compound may be further used and introduced into the molecule. As such a polyol compound, known and conventional compounds can be used. Typical examples are ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol.

1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl -1,5-pentanediol, dichloroneopentyl glycol, dibromoneopentyl glycol, hydroxypivalic acid neopentyl glycol ester, cyclohexane dimethylol,
1,4-cyclohexanediol, spiroglycol,
Examples thereof include tricyclodecane dimethylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, and propylene oxide-added bisphenol A.

Further, as the carboxyl group-containing compound mentioned here, various known and commonly used carboxylic acids, their acid anhydrides, and esterified products of these carboxylic acid compounds and lower alkyl alcohols can be used. Among them, only typical ones are exemplified by maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, het acid, hymic acid,
Chlorendic acid, dimer acid, adipic acid, succinic acid, alkenyl succinic acid, sebacic acid, azelaic acid,

2,2,4-trimethyladipic acid, 1,
4-cyclohexanedicarboxylic acid, terephthalic acid, 2-
Di-lower alkyl of 5-sodium-sulfoisophthalic acid, such as sodium sulfoterephthalic acid, 2-potassium sulfoterephthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, or dimethyl- or diethyl ester. Esters,

Alternatively, orthophthalic acid, 4-sulfophthalic acid, 1,10-decamethylenedicarboxylic acid, muconic acid, oxalic acid, malonic acid, glutanoic acid, trimellitic acid, hexahydrophthalic acid, tetrabromophthalic acid, methylcyclohexene Tricarboxylic acid or pyromellitic acid, or their acid anhydrides, or methanol,
Examples thereof include alcohol ester compounds such as ethanol.

The low-density cross-linking component (B) of the present invention is an essential component for developing processability of a cured product,
Basically, it is necessary to have sufficient elongation to meet the desired workability. Therefore, the structure of the low-density cross-linking component has a relatively large molecular weight, and it is necessary to design so that the cross-linking density does not increase even when cured.

As such a low density crosslinking component (B),
A reactive resin component having a reactivity of 1.0 mmol / g or less can be used, but more specifically, 1.0 mmol / g
An oligomer or polymer having a reactivity of not more than / g, in other words, having a small number of crosslinkable functional groups per molecule is preferable. Polyurethane acrylate is particularly preferable as a material having excellent durability as a low-density crosslinking component and capable of forming a component gradient structure together with the above-mentioned high-density crosslinking component.

When a polyurethane acrylate is used as the low-density cross-linking component (B), it is a polyurethane acrylate having a reactivity of 1.0 mmol / g or less and has a molecular weight of 3,000 to 30,000 and at least one acrylate in one molecule. It is produced by a urethanization reaction of a compound having both a (meth) acryloyl group and a hydroxyl group, a polyol compound, and a polyisocyanate compound.

This polyurethane acrylate having a linear structure is preferable from the viewpoint of workability because it is easy to obtain mechanical properties, particularly elongation. When the molecular weight is less than 3000, it is difficult to obtain sufficient workability, and the molecular weight is 30.
If it exceeds 000, the viscosity becomes high and handling becomes difficult.

As a compound having at least one (meth) acryloyl group and a hydroxyl group in one molecule, which is used as a constituent of the polyurethane acrylate, known and commonly used compounds can be used. Among them, only typical examples are 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth).
Acrylate,

3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, pentaerythritol tri (meth) acrylate or glycidyl methacrylate- (meth ) Acrylic acid adducts, ring-opening reaction products of (meth) acrylate compounds having various hydroxyl groups as described above, ε-caprolactone, and modified products thereof.

As the polyol compound mentioned here, polyether polyol, polyester polyol, alkylene polyol, polycarbonate polyol and the like can be used, and they may be used alone or in combination of two or more kinds, and polyol The molecular weight of the compound is not limited, but preferably 100 or more and 5000 or less.

Here, as the polyether polyol,
Well-known and commonly used ones can be used. Of these, only typical ones are exemplified, polytetramethylene glycol, propylene oxide-modified polytetramethylene glycol, ethylene oxide-modified polytetramethylene glycol, polypropylene glycol, polyethylene glycol. And the like, or polyether polyols obtained by ring-opening polymerization of cyclic ethers using a trifunctional or higher functional polyol as an initiator.

As the polyester polyol, those obtained by the esterification reaction or transesterification reaction of the above-mentioned polyols and the above-mentioned carboxyl group-containing compound or the above-mentioned cyclic ester compound can be used.

Further, as the polycarbonate polyols referred to herein, diphenyl carbonate, bischlorophenyl carbonate, dinaphthyl carbonate, phenyl-toluyl-carbonate, phenyl-chlorophenyl-carbonate or 2-tolyl-4-tolyl-carbonate, or a diaryl- or dialkyl carbonate such as dimethyl carbonate or diethyl carbonate;

Reaction of various polyols such as those listed above with polyols represented by those obtained by transesterification of polyester diols such as reaction products of polycarboxylic acids as described above. And carbonate derivatives of the class obtained by.

It is needless to say that the polyisocyanate may be used alone or in combination with the isocyanurate-form polyisocyanate and the isocyanate compound. To give only examples, various alicyclic diisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, dicyclohexylmethane diisocyanate or isophorone diisocyanate, hydrogenated xylylene diisocyanate;

Further, various compounds such as various aliphatic diisocyanate compounds such as hexamethylene diisocyanate or lysine diisocyanate can be used. Further, considering weather resistance and durability, it is preferable to use hydrogenated diphenylmethane diisocyanate as the polyisocyanate.

It is well known that various raw materials of polyurethane acrylate used as the low-density cross-linking component (B) have a wide range of mechanical properties by changing the adjustment according to the desired physical properties. . In the present invention, from the viewpoint of durability, the polyol compound is preferably a polyester polyol or polycarbonate carbonate, and in order to have sufficient processability, a polyester polyol having an aliphatic structure. Alternatively, polycarbonate carbonate is preferred.

The one having an alicyclic structure has a large elastic modulus due to its rigidity due to the molecular structure, but is difficult to be stretched. Therefore, as the structure of the polyester polyol and the polycarbonate carbonate, it is preferable to use an aliphatic polybasic acid compound, and a polyaliphatic compound can be partially used.

The composition ratio of the high-density crosslinking component (A) and the low-density crosslinking component (B) of the resin composition according to the present invention is (A) /
(B) is preferably in the range of 90/10 to 10/90,
The range of 90/10 to 50/50 is particularly preferable in terms of the balance between workability and stain resistance.

The fact that the cured product according to the present invention has a gradient structure can be easily determined by swelling the cured product in a specific solvent and examining the presence or absence of its deformation. That is, the swelling property of the gel is closely related to its crosslink density, and the higher the gel swelling ratio, the lower the crosslink density. (Encyclopedia of Polymer
r Technology 4: 63-65 (196)
6 years) Inter-science publication)

That is, when the crosslinked density on the surface of the cured product is higher than that inside the cured product or on the side of the coated substrate, the swelling ratio of the gel is different due to the composition gradient structure.
Deformation occurs. When the cured product is swollen with a solvent, the swelling ratio of the surface of the cured product is relatively small, and the volume expansion is large inside the cured product, on the back surface of the cured product, or on the interface side of the substrate. Since the swelled body of the cured product warps to the side), it can be easily confirmed that it has an inclined structure. Such deformation does not occur when there is no component gradient structure between the interfaces or inside the cured product.

In order for the cured product as a whole to have excellent processability, it is necessary to set the average crosslink density of the cured product to a low level, and a structure in which the highly crosslinked component is concentrated is required only on the very surface. Therefore, in the surface region where the highly cross-linking component is concentrated, the highly cross-linking component is densely distributed and concentrated in the depth direction of about 1 to 3 microns from the air interface, particularly in the range of 100 angstrom, and a component gradient structure is formed. Must have been done.

Further, a polyester acrylate (A) forming a graded structure and a polyurethane acrylate (B)
In the cured product of the composition (1), the heat treatment causes the polyester acrylate (A) to concentrate at the air interface. Therefore,
The surface cross-linking density is increased, resulting in good stain resistance. As a qualitative and quantitative method of concentration at this time, surface analysis described below is used as an effective means.

A specific method of surface analysis is ATR.
The component structure of the surface of the cured product can be determined by infrared spectrum of the surface such as -IR, quantification of atoms by ESCA, and measurement of atomic bonding state. (Miki et al., Convertec 199
0/8 page 1, Convertec 1991/1 page 1,
Macromolecules 1991, 24, 7
99-805)

ATR-IR method (Attenuated Total Refra
ction-IR method, infrared total reflection absorption spectrum method) is a type of infrared spectroscopic analysis method. Infrared light has an angle of incidence that exceeds the critical angle, When moving to a small sample, it is totally reflected at this interface, but at this interface, it penetrates into the sample by a depth proportional to the wavelength and is reflected. If the sample absorbs light, part of the light is absorbed. This is an analysis method using the principle described above. (Experimental Chemistry Lecture 6 Spectroscopy I 4th Edition, published by The Chemical Society of Japan, Maruzen Co., Ltd.) This enables measurement up to several microns in the depth direction from the surface of the cured product.

X-ray photoelectron spectroscopy (ESCA, Electr
on Spectroscope for Chemical Analysis or XP
S, X-Ray Photoelectron Spectroscope)
It is a spectroscopy using photoelectrons generated by irradiating a ray. This analysis is performed from the surface of the sample to several tens to about 1
It is possible to selectively measure up to 00 angstroms, and it is possible to obtain information on local bonding states of constituent elements. With these analytical instruments, the characteristic structure of the cured product according to the present invention can be known.

For example, in the case of a composition in which polyester acrylate is used as the high density crosslinking component (A) and polyurethane acrylate is used as the low density crosslinking component (B), the polyurethane acrylate has N atoms in the urethane bond. Since N atom does not exist in the polyester acrylate, N in the depth direction in ESCA is
The abundance ratios of the high-density cross-linking component and the low-density cross-linking component were quantified by atom determination within a range of about 100 Å from the surface of the cured product, and the high-density cross-linking component (A) was concentrated on the surface of the cured product. You can check that. Similarly, focusing on oxygen, nitrogen, and other marker atoms, the content ratio in the depth direction can be calculated from the theoretical content value of each component.

As a result of analyzing the active energy ray resin cured product having the component gradient structure of the present invention by the above-mentioned analysis method,
As a structure having good surface properties, it is preferable that the surface has a high density crosslinking component (A) at a concentration of 60% or more. Further, when polyester acrylate and polyurethane acrylate are used, the composition of the surface is preferably 1/3 or less of the theoretical nitrogen atomic weight.

More specifically, after curing, in the resin component on the surface of the cured resin, the high-density crosslinking component (A) has a composition ratio (A) / (B) of the resin composition before curing, specifically, Specifically, the composition ratio of the high-density crosslinking component (A) is more than (A) / (B) = 25/75, that is, (A) / (B) = 30.
It is necessary to exist at / 70 to 100/0.

Further, the high density cross-linking component (A) is distributed in the highest concentration on the surface of the cured product, and the composition has a graded structure in which the content of the high density cross-linking component (A) decreases in the depth direction. Is preferable, and the cured product of the present invention is 100 from the surface of the cured product.
Approximate depth (A) / (B) = 60 for Angstrom depth
/ 40 to 100/0, and (A) / (B) = 30/70 to 60 at a depth of 3 microns from the surface of the cured product.
It is in the range of / 40.

The transfer of the curing component in the resin composition to the component gradient structure requires some external or internal stimulus, and basically, the supply of energy such as light or heat serves as the stimulus. . Specifically, it is necessary to supply transition energy to the component gradient structure by heat treatment before curing, the temperature of the cured composition is 50 ° C. or higher, preferably 70 ° C. or higher, and the active energy ray curable type is used. A temperature not higher than the decomposition temperature of the resin composition, specifically a temperature not higher than 250 ° C., more preferably 2
Heat treatment is performed at a temperature of 00 ° C. or lower.

The heat treatment time varies depending on the resin composition of the composition used, and a shorter time is preferable from the viewpoint of productivity, but usually 10 seconds or more is required. The heating method is
It can be performed by a usual heating method, hot air, microwave, ultrasonic wave, infrared ray, far infrared ray.

The active energy ray used for resin curing in the present invention is a general term for electron beam, α ray, γ ray, X ray, neutron ray, ultraviolet ray, and other ionizing radiation and light. In the present invention, when the resin composition of the present invention is cured using ultraviolet rays as active energy rays, a photo (polymerization) initiator which dissociates by ultraviolet rays having a wavelength of 1000 to 8000 angstroms to generate radicals is also used. It is preferable to use.

As the photo (polymerization) initiator, any of known and commonly used ones can be used, and typical examples thereof include acetophenones, benzophenone derivatives, Michler's ketone, benzine and benzyl derivatives.
Benzoin derivatives, benzoin methyl ethers, α-
Acyloxime esters, thioxanthones, anthraquinones and their various derivatives such as 4-dimethylaminobenzoic acid

4-dimethylaminobenzoic acid ester,
Alkoxy acetophenone, benzyl dimethyl ketal, benzophenone, alkyl benzoyl benzoate, bis (4-dialkylaminophenyl) ketone, benzyl, benzoin, benzoin benzoate, benzoin alkyl ether, 2-hydroxy-2-methylpropiophenone, 1 -Hydroxycyclohexyl phenyl ketone, thioxanthone, 2,4,6-trimethylbenzoyldiphenoylphosphine oxide,

2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and the like can be mentioned. . Further, a known and commonly used photosensitizer may be used in combination with such a photo (polymerization) initiator.

As the photosensitizers, only typical ones will be exemplified. Amines, ureas, sulfur-containing compounds, phosphorus-containing compounds, chlorine-containing compounds, nitrites or other nitrogen-containing compounds. Is.

After coating the active energy ray-curable resin composition of the present invention on a target object, it is heat-treated at a temperature of 50 ° C. or higher and a decomposition temperature of the active energy ray-curable resin composition or lower, and then by electron beam irradiation. The electron beam used for curing is an electron beam having an acceleration energy of 0.1 to 3.0 MeV, and is a Cockcroft type, a Cockcroft Walton type, a Pandegraph type, a resonance transformer type, an insulating core transformer type, a straight type, a dynamic type. Various electron beam accelerators such as a tron type, a high frequency type, and an electron curtain type can be used. The irradiation dose is not particularly limited, but a range of 0.1 to 20 Mrad is usually suitable.

As the atmosphere for performing active energy ray curing, the higher the temperature of the cured composition, the better the reactivity, and the surface temperature of the cured product is preferably 40 ° C. or higher. Further, from the viewpoint of preventing inhibition of polymerization of oxygen, it is desirable to carry out a reaction of irradiation with an active energy ray and curing in an inert gas. Examples of the inert gas include nitrogen gas, carbon dioxide gas, argon, helium, krypton, and the like, which are preferable. When the residual oxygen concentration is 1% or less, a good cured product can be obtained.

Further, the cured resin composition of the present invention may further contain other components, if necessary. As these other components, a solvent that does not inhibit curing by active energy rays, a reactive diluent, a polymer, an inorganic filler,
Inorganic pigments or organic pigments, and additives such as polymerization inhibitors, antioxidants, dispersants, surfactants, light stabilizers, light absorbers and leveling agents can be added.

As the above-mentioned solvent, only representative ones are exemplified, and aromatic hydrocarbons such as toluene or xylene; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone; methyl acetate, Esters such as ethyl acetate or butyl acetate; alcohols such as methanol, ethanol, propanol or butanol; aliphatic hydrocarbons such as hexane and heptane, cellosolve acetate, carbitol acetate, dimethylformamide or tetrahydrofuran. .

The reactive diluent is widely used from the monofunctional to the polyfunctional ones for the purpose of solvent-free and high solidification, but impairs the formation of the gradient component structure of the present invention. It should be used in a range that does not exist.

Of the reactive diluents, only typical ones are exemplified. Isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate. , Tetrahydrofurfuryl (meth) acrylate, adamantyl (meth)
Acrylate, hydrogenated rosin (meth) acrylate, 2-
Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-hydroxybutyl acrylate, N-vinylpyrrolidone, 1-vinylimidazole,

Tetrahydrofurfuryl (meth) acrylate, carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentadiene (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,6- Hexanediol di (meth) acrylate, polyethylene glycol di (meth)
Acrylate, hydroxypivalic acid ester neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate,

Modified with pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate or dipentaerythritol hexa (meth) acrylate, or a cyclic ether compound such as ethylene oxand or propylene oxide of the above reactive diluent ( And a (meth) acrylate compound.

The above-mentioned polymer may be either saturated or unsaturated, and the polymer can be added for the purpose of modifying the physical properties of the cured coating film or reducing the cost. As a concrete example,
Examples thereof include acrylic resin, polyester resin, polyamide resin, epoxy resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, fibrin resin and chlorinated polypropylene. These also need to be used within a range that does not impair the formation of the gradient component structure of the present invention.

Typical examples of the above-mentioned inorganic fillers include barium sulfate, calcium carbonate, talc, mica,
Extension pigments such as clay, barium carbonate, gypsum, white alumina, silica, calcium silicate, magnesium carbonate silica powder, colloidal silica, asbestos powder, aluminum hydroxide, zinc stearate;

Chromates such as yellow lead, zinc chromate or molybdate orange, ferrocyanides such as navy blue, titanium oxide, zinc white, red iron oxide, metal oxides such as iron oxide and chromium carbide green, cadmium yellow and cadmium red. Alternatively, a metal sulfide such as mercury sulfide, a sulfate such as selenide or lead sulfate, a silicate such as ultramarine, a carbonate, a phosphate such as cobalt violet or manganese purple, or an aluminum powder,
Zinc dust, brass powder, magnesium powder, iron powder, metal powder such as copper powder or nickel powder, and further inorganic pigments such as carbon black;

Alternatively, there are organic pigments such as copper phthalocyanine pigments such as azo pigments, phthalocyanine blue and phthalocyanine green, or quinacridone pigments. Furthermore, any other coloring, rust preventive, and extender pigments may be used, and two or more kinds of them may be used in combination, but when ultraviolet rays are used as active energy rays, they can secure the amount of ultraviolet rays necessary for curing. It must be used within the range of transparency.

Examples of the cured product of the composition of the present invention include a cured cured resin itself, or a cured composition obtained by coating the resin composition on metal, plastics, paper, glass, woodworking and the like and then curing it. I can. As a cured product coated on metal, a cut plate as an original plate or a coiled iron plate,
Electrogalvanized steel sheet, hot-dip galvanized steel sheet, or those that have undergone chemical conversion treatment such as chromic acid, phosphoric acid treatment, aluminum plate, stainless steel plate or steel plate, etc.
It can be a cured product. As the cured product of the present invention,
It is particularly preferable to coat and harden an (electric) galvanized steel sheet from the viewpoint of balance of surface aesthetics, cost, corrosion resistance and the like.

Further, in the production of the cured product of the present invention, the pretreatment applied to the metal plate can be carried out by a conventionally known method, if necessary. For example, the metal plate is already subjected to the chemical conversion treatment in the production process. For the steel sheet, it is sufficient to simply perform the pretreatment of only the cleaning treatment, but for the steel sheet not subjected to the chemical conversion treatment, it is preferable to perform the chemical conversion treatment according to the material thereof.

A primer may be used between the original plate and the layer of the resin composition of the present invention to improve adhesion, corrosion resistance and rust prevention. As the composition of this primer, epoxy, modified epoxy, vinylphenol, epoxyacrylic, polyester resin, etc. can be used, and there is no restriction on the curing method of heat, electron beam, ultraviolet ray, far infrared ray and the like.

The primer can be applied by a usual method such as natural roll coating, reverse roll coating, curtain flow coating, spray coating, or the like. It is desirable that the film thickness of the primer is about 1 to 10 μm, preferably about 2 to 5 μm.

The resin composition according to the present invention can be applied directly to a base plate or to a primer-coated plate by a conventional method such as natural roll coating, reverse roll coating, curtain flow coating or spray coating. Can be done at The film thickness is 1 to several 10
It is desired to be 0 micron, preferably about 5 to 100 micron. Also, as mentioned earlier,
Depending on the conditions such as film thickness, in order to obtain a preferable liquid viscosity,
Although a solvent can be added, it is desirable to remove this solvent before curing with an electron beam.

In addition, also in the case of coating various plastic materials and glass materials, the surface of the plastic or glass may be treated with plasma, primer treatment, silane coupling agent and the like, if necessary.

The active energy ray resin cured product produced by the production method of the present invention using the resin composition of the present invention has a component gradient structure of a high-density cross-linking component in the depth direction from the surface of the cured resin and is cured. The resin surface has stain resistance and solvent resistance, and the elongation at break of the cured product itself is 80% or more, and it has excellent processability.

The fact that the surface of the cured product according to the present invention has good stain resistance can be specifically evaluated by a method according to JIS K5400 as a test method of a coating film. As a concrete test method of stain resistance, as a pollutant material,
Mark the cured coating with a black or red oil-based marking pen, leave it for 18 hours or longer, and soak the mixed solvent of ethanol / petroleum benzine (1/1 weight ratio) in gauze to paint the coating. After the trace is wiped off, the remaining red color is measured with a color difference meter.

Further, the solvent resistance of the cured product according to the present invention shows good solvent resistance equivalent to that of the widely used coated products, and the cured product surface of the present invention is highly crosslinked. It means that there is. Further, since the cured resin product according to the present invention has excellent workability as a whole, the elongation at break of the cured product is 80% or more, and it is not necessary to set an upper limit thereof, but the elongation at break of the cured product of the present invention is not limited. Is usually 80% or more and 300% or less, and has extremely excellent workability.

[0104]

EXAMPLES Next, the present invention will be described more specifically with reference to examples, comparative examples and test result examples, but the present invention is not limited to these examples. In the following, all parts and% are based on weight unless otherwise specified.

(Synthesis Example 1) (Synthesis Example of Intermediate a-1i of Polyurethane Acrylate a-1) A flask equipped with a thermometer, a stirrer and a condenser was charged with 222 parts of isophorone diisocyanate.
The temperature was raised to 5 ° C. Next, 2-hydroxy acrylate
116 parts was reacted dropwise for 2 hours. After the completion of the dropping, the temperature is raised to 75 ° C. and the reaction is carried out for 5 hours.
-1i was obtained. The remaining NCO% at this time is 12.4%
Met.

(Synthesis example 2) (Synthesis example of polyurethane acrylate a-1) 5019 parts of ethyl acetate, 3-methyl-1,5-pentanediol and adipic acid were placed in a flask equipped with a thermometer, a stirrer and a condenser. Polyester diol (molecular weight 500, hydroxyl value 224.4 KOH-mg / g)
3037.5 parts and 3-methyl-1,5-pentanediol 666.7 parts were charged and uniformly dissolved.

After the temperature was raised to 65 ° C., 2810 parts of dicyclohexylmethane diisocyanate was charged,
The reaction was carried out at 65 ° C for 5 hours. The isocyanate value at this time was 0.05%. Next, a obtained in Synthesis Example 4
1014 parts of -1i was charged and reacted at 70 ° C for 8 hours. It was confirmed by IR spectrum that there were no residual isocyanate groups, and the number average molecular weight was about 720.
A solution of the target urethane acrylate (a-1) having 0 and a nonvolatile content of 60% was obtained.

(Synthesis Example 3) (Synthesis Example of Polyurethane Acrylate a-2) A flask equipped with a thermometer, a stirrer and a condenser was charged with 4800 parts of ethyl acetate and 2882 parts of dicyclohexylmethane diisocyanate and heated to 65 ° C. did. Next, poly 1,6 hexane carbonate diol (molecular weight 600, hydroxyl value 187 KOH-mg / g) 360
0 parts and 472 parts of 1,6-hexanediol were charged and reacted at 65 ° C. for 5 hours.

At this time, the isocyanate value was 0.72%
Met. Next, 235 g of hydroxyethyl acrylate
Was charged, and the mixture was further reacted at the same temperature for 3 hours, and it was confirmed by IR spectrum that residual isocyanate groups were not present. The target urethane acrylate (a having a number average molecular weight of about 7,200 and a nonvolatile content of 61%) (a -2) solution was obtained.

(Synthesis Example 4) (Synthesis Example of Polyurethane Acrylate a-3) A flask equipped with a thermometer, a stirrer and a condenser was charged with 5500 parts of ethyl acetate and 3144 parts of dicyclohexylmethane diisocyanate and heated to 65 ° C. did. Next, 4000 parts of 3-methyl-1,5-pentanediol and adipic acid polyester diol (molecular weight 1000, hydroxyl value 112.2 KOH-mg / g), and 3-
826 parts of methyl-1,5-pentanediol was charged and the reaction was carried out at 65 ° C. for 5 hours.

The isocyanate value at this time was 0.63.
%Met. Then hydroxybutyl acrylate 260
Then, the reaction was carried out at the same temperature for 3 hours, and it was confirmed by IR spectrum that residual isocyanate groups were not present. The target urethane acrylate (number average molecular weight: about 8300, nonvolatile content: 60%) a-3)
A solution of

(Synthesis Example 5) (Synthesis Example of Polyester Acrylate b-1) A flask equipped with a thermometer, a stirrer and a condenser was charged with 254 parts of dipentaerythritol and 912 parts of epsilon caprolaton and heated to 170 ° C. The ring-opening reaction was performed. Next, 432 parts of acrylic acid was charged and reacted at 140 ° C. for 4 hours. A target polyester acrylate (b-1) having an acid value of 0.2 KOH-mg / g was obtained.
The specific gravity of this product is 1.12 g / cm ³ (25 ° C),
The molecular weight was about 1500 and was a hexafunctional polyester acrylate.

(Synthesis Example 6) (Synthesis Example of Polyester Acrylate b-2) In a flask equipped with a thermometer, a stirrer and a condenser, 272 parts of pentaerythritol and 1 part of succinic anhydride were prepared.
00 parts were charged, dehydration condensation was carried out at 170 ° C. for 5 hours, and then 684 parts of epsilon caprolaton was charged to 170 parts.
The ring-opening reaction was carried out at 0 ° C for 5 hours. Then acrylic acid 432
A part was charged and the reaction was carried out at 140 ° C. for 4 hours. A target polyester acrylate (b-2) having an acid value of 0.2 KOH-mg / g was obtained. The specific gravity of this product is 1.1
At 3 g / cm ³ (25 ° C.), the molecular weight was about 1470, and it was a hexafunctional polyester acrylate by design.

(Synthesis Example 7) (Synthesis example of low-density cross-linking component polyurethane acrylate c-1 for comparison) A flask equipped with a thermometer, a stirrer and a condenser was charged with 962 parts of ethyl acetate and 444 parts of isophorone diisocyanate. The temperature was raised to 65 ° C. Next, polyester diol of 3-methyl-1,5-pentanediol and adipic acid (molecular weight 1000, hydroxyl value 112.2)
KOH-mg / g) 1000 parts was charged and the mixture was heated at 65 ° C. for 5
The reaction was carried out over time. The isocyanate value at this time is 3.
It was 50%.

Next, hydroxyethyl acrylate 232
Then, the reaction was carried out at the same temperature for 3 hours, and it was confirmed by IR spectrum that residual isocyanate groups were not present. The target urethane acrylate (number average molecular weight: about 1700, nonvolatile content: 60%) c-1)
A solution of

(Synthesis Example 8) (Synthesis Example of Comparative High-Density Crosslinking Component Urethane Acrylate c-2) A flask equipped with a thermometer, a stirrer, and a condenser was charged with 222 parts of isophorone diisocyanate.
The temperature was raised to 5 ° C. Next, 232 parts of hydroxyethyl acrylate was added dropwise over 2 hours, and further reacted at the same temperature for 3 hours. By IR spectrum, it was confirmed that there was no residual isocyanate group, and a high-density cross-linking component urethane acrylate (c-2) for comparison was obtained.

(Examples 1 to 5) (Experiments with a clear film by electron beam curing) The paint formulations shown in Table 1 were prepared and coated on glass so that the dry coating thickness would be 50 microns. This one is 100 ℃
Oxygen concentration of 20
Acceleration voltage 175 under nitrogen atmosphere of 0-300ppm
Irradiate 6Mrad electron beam with kV, acceleration current 4mA,
A cured coating film was prepared. The electron beam irradiation was performed at room temperature of 25 ° C. PETA in Table 1 represents pentaerythritol triacrylate (molecular weight 298). Table 2 shows the evaluation results.
3,4.

(Comparative Examples 1 to 4) The coating materials shown in Table 1 were blended, and cured coatings were prepared in the same manner as in Examples 1 and 2. The evaluation results are shown in Tables 2, 3 and 4.

[0119]

[0120]

[0121]

[0122]

[Evaluation Method] (Theoretical N Amount) The theoretical N amount was calculated by calculating the theoretical number of moles of nitrogen atoms in the resin from the charged amount and the reaction, and shown by the atom mole% of nitrogen atoms in the constituent atoms of the resin. . Table 5 shows the N atom content of the resins obtained in various synthesis examples.

[0124]

(Gel swelling) The cured product was Solvesso 100 /
It was immersed in a mixed solvent of acetone = 70/30 (weight ratio) for 3 minutes, taken out into the air, and the deformation of the cured product was observed. The results of deformation are shown by the symbols shown below. ++: The curl was largely curled on the air interface side. +: Curled on the air interface side of the cured product. +-: The cured product was hardly deformed. -: Cured on the side of the substrate separation interface of the cured product. -: The curl was largely curled on the side of the substrate peeling interface.

(Measurement of Surface N Amount) The surface N amount was measured by Shimadzu Corporation ESCA-850 (X-ray source Mg anode (8K
V, 30 mA)), and measured in the depth direction at several tens of angstroms. The numerical values are shown in atomic mol% of nitrogen atoms in the constituent atoms (C, N, O).

(Elongation at Break) A cured sample was cut into a 1 cm width, and this was subjected to a tensile test with a universal tensile tester (Tensilon: manufactured by Toyo Baldwin Co., Ltd.) at a chuck distance of 2 cm and a crosshead speed of 20 mm / min. The elongation until breakage was calculated by the following formula. Elongation at break (%) = (ab) / b × 100 where a: sample length at break (cm) b: initial sample length (cm)

(High Density Crosslinking Component Surface Content) From the surface N content measured by ESCA, the surface high density crosslinking component content was calculated by the following formula. High-density cross-linking component surface content (%) = {(a-w) / (a
-B)} × 100 where a: mol atom% of low-density crosslinking component N atom (theoretical value) b: mol atom% of high-density crosslinking component N atom (theoretical value) w: surface N atom of ESCA Mol atom%

(Stain resistance) A red oil-based magic pen is applied to the cured coating film, and it is left at room temperature for 24 hours. Thereafter, a mixed solvent of ethanol / petroleum benzine (1/1 weight ratio) was dipped in the gauze to wipe off the traces of the drawing lines of the magic pen paint, and the remaining red color was measured with a color difference meter. The smaller the value of the color difference, the less the pigment remaining on the coated surface and the better the stain resistance.

(Surface Micro Hardness) Surface micro hardness meter (manufactured by Shimadzu Corporation: dynamic ultra micro hardness meter DUH-200)
And the dynamic hardness expressed by the following formula was shown as the surface microhardness. The test load is 2.00g
, The displacement scale is 5 μm, and the indenter is DH1.
5 (115 ° triangular pyramid indenter) was used. In addition, the test results are shown as an average value of the measurement values obtained by repeating 5 times.

Dynamic hardness (H) = F / αD ² where, H: dynamic hardness (g / μm ² ), F: load in the indenter pushing process (g) α: indenter-specific shape constant D: indentation Depth (μm) αD ² : Surface area of pressed indenter (μm ² )

(Workability) The cured coated steel sheet was bent at 180 ° at 0T, 1T and 2T, and the presence or absence of cracks was evaluated. ⊚: No cracks. ◯: A little crack that can be confirmed with a 10 times magnifying glass. Δ: There are some cracks that can be visually confirmed. ×: The coating film does not break, but large cracks are formed. XX: The coating film breaks.

The clear film cured with the formulation according to Table 1 shows, as is clear from the experimental results of gel swelling in Table 2,
It is proved that the cured product of the present invention has a gradient of the high-density crosslinking component, and as a result, the crosslinking density at the air interface is high. Further, in Comparative Examples 1 and 2, deformation due to gel swelling is slightly observed on the substrate side, but this is due to polymerization inhibition by a trace amount of oxygen at the time of curing, as compared with the substrate side in which the crosslinking at the air interface is in an anaerobic state, It is presumed that it was a little less.

Table 4 shows the results of calculating the surface content of the high-density crosslinking component from the amount of nitrogen in the surface resin of the cured product. The amount of nitrogen atoms in the resin on the surface of the cured product of the present invention shows an extremely high value as compared with the theoretical composition, and the component-gradient cured products in the examples have a very small surface (several tens of angstroms).
It can be seen that the high-density cross-linking component is concentrated by 60% or more in the range of (m).

On the other hand, the nitrogen atom weights of the comparative examples are similar to the theoretical values. Furthermore, the cured product of the present invention has excellent surface stain resistance, and the elongation at break is much higher than 150% for all cured products. In the comparative example, the stain resistance is not good and the elongation at break is 50%.
It was below.

(Example 6) (Influence of heat treatment for electron beam curing) The coating materials shown in Table 6 were blended to give a dry coating film thickness of 5 on glass.
Painted to 0 micron. Next, this sample was subjected to solvent removal for 5 hours at 25 ° C. under a reduced pressure of 5 mmHg. Furthermore, after heat-treating this sample in a dryer at 100 ° C. for 3 minutes, the oxygen concentration is 200 to 300 pp.
In a nitrogen atmosphere of m, an irradiation voltage of 175 kV and an acceleration current of 4 mA were applied to a 6 Mrad electron beam at room temperature of 25 ° C. The evaluation results are shown in Tables 7 and 8 and FIG.

(Comparative Example 5) A sample was prepared with the same resin composition and curing method as in Example 6 except that the heat treatment was not performed. The evaluation results are shown in Tables 7 and 8 and FIG.

[0138]

[0139]

[0140]

Example 6 and Comparative Example 5 are the results of examining the effect of heat treatment. As is clear from Table 7, in Example 6 in which the heat treatment was performed, the high-density cross-linking component was concentrated on the surface of the cured product, and the stain resistance of the surface and the elongation at break showed extremely good physical property values. However, when the heat treatment was not performed, the stain resistance was poor even though the elongations were almost the same.

Table 8 and FIG. 1 show the surface microhardness measured by a microhardness meter. As is clear from the results of Table 8 and FIG. 1, the composition having the component gradient structure is 0 to 5 μm. It is understood that the microhardness up to a certain degree is high, and the hardness is higher as it is closer to the surface.

(Example 7) (Curing by UV) The coating composition shown in Table 9 was prepared, and a dry coating film thickness of 50 was obtained on glass.
Painted to be micron. This was heat-treated in a dryer at 100 ° C. for 3 minutes, and then the sample was placed in a quartz glass sealable box, and the air in the box was replaced with nitrogen. The residual oxygen concentration at this time is 500 to 800 p
It was pm. Next, this sample was irradiated with ultraviolet rays three times with a high-pressure mercury lamp (80 W / cm) under the conditions of an irradiation distance of 15 cm and a line speed of 10 m / min to cure the sample. The evaluation results are shown in Table 10.

Comparative Example 6 A coating composition shown in Table 9 was prepared,
A cured coating film was prepared in the same manner as in Examples 1 and 2.
Irgacure 184 in the table represents 1-hydroxycyclohexyl phenyl ketone which is a photoinitiator. Table 10 shows the evaluation results.
Shown in.

[0145]

[0146]

(Examples 8 to 10) The coating materials shown in Table 11 were blended and dispersed with a high speed disperser at 1000 rpm for 1 hour. This coating composition was applied to an electrogalvanized steel sheet (0.6 mm thick) coated with a thermosetting epoxy primer with a dry coating thickness of 2 microns so that the dry coating thickness would be 25 microns.

This was heat-treated in a dryer at 130 ° C. for 1 minute, and then, in a nitrogen atmosphere having an oxygen concentration of 200 to 300 ppm, an acceleration voltage of 175 kV and an acceleration current of 4 m.
At A, it was irradiated with 8 Mrad electron beam. At this time, the temperature of the film surface of the coating film at the time of electron beam irradiation was 70 ° C. before the electron beam irradiation and 50 ° C. immediately after the irradiation. In each of Examples 8 to 10, a white enamel paint was formed using titanium oxide in each of the formulations of Examples 1, 2, and 4. The evaluation results are shown in Table 12.

(Comparative Examples 7 to 9) Coating compositions shown in Table 11 were applied, and coated steel sheets were prepared in the same manner as in Examples 9 to 11. The TiO ₂ in the table is titanium oxide (Type Peak CR
-93; manufactured by Ishihara Sangyo Kaisha, Ltd.). Titanium oxide was set at PWC = 45% in terms of paint solids. The nonvolatile content of the paint was 55%. Comparative Examples 7, 8 and 9
Is a white enamel paint with titanium oxide added to the formulations of Comparative Examples 1, 3 and 4, respectively. The evaluation results are shown in Table 12.

(Comparative Example 10) (Conventional product: Thermosetting type) Oil-free alkyd resin 106.3 parts (nonvolatile content 4
To 0%, hydroxyl value 24 KOH-mg / g), 25 parts of butylated melamine resin (nonvolatile content 40%) was added, and further 67 parts of titanium oxide (CR-93: manufactured by Ishihara Sangyo Co., Ltd.) was added, Dispersion was performed at 1000 rpm for 1 hour using a high speed disperser. This coating composition was applied to an electrogalvanized steel sheet (0.6 mm thick) coated with a thermosetting epoxy primer to a dry coating film thickness of 2 μm so that the dry coating film thickness would be 25 μm. This was heat-cured for 1 minute in a dryer at 260 ° C. The evaluation results are shown in Table 12.

[0151]

[0152]

(Examples 11 to 13) [0153] Examples 11 and 12 were prepared with the same coating composition as Examples 8, 9 and 10 shown in Table 11.
Paints for 13 (Paint formulations of Example 8 and Example 11 are the same, Paint formulations of Example 9 and Example 12 are the same, Paint formulations of Example 10 and Example 13 are the same) Was the same) was prepared and dispersed by a high speed disperser at 1000 rpm for 1 hour. This paint was applied to a glass plate having a thickness of 5 mm so as to have a dry film thickness of 25 μm.

This was heat-treated in a dryer at 130 ° C. for 1 minute, and then, in a nitrogen atmosphere having an oxygen concentration of 200 to 300 ppm, an acceleration voltage of 175 kV, an acceleration current of 4 mA, 8 Mr.
The electron beam of ad was irradiated. At this time, the temperature of the coating film surface at the time of electron beam irradiation was 70 ° C. before the electron beam irradiation and 50 after the irradiation.
It was ℃. The evaluation results are shown in Table 13.

(Comparative Examples 11 to 13) Comparative Examples 11, 12 and 1 were prepared by using the same coating composition as Comparative Examples 7, 8 and 9 shown in Table 11.
Coating composition for 3 (the coating composition of Comparative Example 7 and the coating composition of Comparative Example 11 are the same, the coating composition of Comparative Example 8 and the coating composition of Comparative Example 12 are the same, the coating composition of Comparative Example 9 and the coating composition of Comparative Example 13) Was prepared) and a cured coating film was prepared in the same manner as in Examples 11 to 13. The evaluation results are shown in Table 13.

[0156]

(Example 14) A coating material similar to that of Example 9 was prepared and coated on a glass plate so as to have a dry film thickness of 25 microns, and the change in stain resistance when the heat treatment conditions were changed was examined. It was In the experiment, a sample was used, which was previously dried under reduced pressure at room temperature to sufficiently remove the solvent so that there was no influence of the solvent. The heat treatment conditions of this coated plate were changed, and electron beams were irradiated under the same conditions as in Example 9. After curing, the cured coating film was peeled off from the glass plate, and its stain resistance was examined. The results are shown in FIGS. 2 and 3.

It can be seen from FIG. 2 that the formation rate of the component gradient structure is related to the temperature of the heat treatment, and the higher the heat treatment temperature, the faster the formation rate of the gradient structure.

Further, it is understood that the component gradient structure cannot be obtained without the heat treatment. Further, from FIG. 3, on the back surface, since the stain resistance is hardly changed by the heat treatment, it is possible to form the component gradient structure in such a manner that the heat treatment causes the dense interface component to be concentrated on the air interface side. Recognize.

(Example 15) A coating material similar to that of Example 9 was prepared and coated on a glass plate so as to have a dry film thickness of 25 µm. After heat treatment at 130 ° C. for 1 minute, the surface temperature of the coating film immediately before electron beam irradiation was changed to measure the stain resistance. The results are shown in Table 14.

[0161]

From FIG. 2, when the heat treatment temperature is high, the stain resistance is improved in a short time, but when the temperature is lower than 50 ° C., the stain resistance is not improved or it takes a long time to improve the stain resistance. it is obvious. From Table 14, the ones which were irradiated and cured at 70 ° C showed better results than those which were cured at 25 ° C. Further, as is clear from FIG. 3, the stain resistance of the cured product surface (air interface side) is 130
It is known that it does not change even if the heat treatment time is long at 0 ° C, but it improves in a short time.

[0163]

INDUSTRIAL APPLICABILITY The present invention has excellent gloss, stain resistance, solvent resistance, and flexibility, so that it can be bent,
Provided is an active energy ray-curable resin composition, a cured product, and a method for producing the cured product, which has high workability capable of being subjected to post-processing such as stretching and deformation and is suitable for precoat coating of glass such as metal and plastic, and glass coating. it can.

[Brief description of drawings]

FIG. 1 is a cured product of active energy rays of the present invention (Example 6).
3 is a graph showing the relationship between the depth (μm) from the surface of the cured product of Comparative Example 5 and the dynamic hardness (surface microhardness, g / μm ² ). The white squares show the relationship between the depth (μm) from the surface of the cured product of Example 6 and the comparative example 5 and the dynamic hardness (surface microhardness, g / μm ² ).

FIG. 2 is a graph showing the relationship between heat treatment temperature (° C.), heat treatment time (seconds) and stain resistance of the cured product of the active energy ray of the present invention. (Example 14) In the figure, the black square in (1) is a heating temperature of 25 ° C, the left part of (2) is a black temperature of 50 ° C, the right part of (3) is a black temperature of 70 ° C. C., the open square in (4) shows the heating temperature at 100.degree. C., and the black diamond in (5) shows the relationship between the heat treatment time at 130.degree. C. and the stain resistance.

FIG. 3 shows the relationship between heat treatment time (seconds) and stain resistance on the front and back surfaces of the cured product of the active energy ray of the present invention which was heat-treated at 130 ° C. (Example 14) In the figure, the black squares show the relationship between the heat treatment time (° C) and the stain resistance of the cured product surface (air interface side) and the open squares the cured product back surface.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area C09D 175/14 PDZ

Claims (25)

[Claims] 1. A high-density cross-linking component (A) and a low-density cross-linking component (B) are contained in at least two kinds of resin components, and the high-density cross-linking component ( (A) is (A) / of the resin composition before curing
A component-gradient structure that exists in excess of the composition ratio of (B) and in which the composition ratio (A) / (B) of the high-density crosslinking component (A) continuously decreases in the depth direction from the surface of the cured resin. An active energy ray curable resin composition to be formed. 2. The high-density crosslinking component (A) is a reactive resin component having a trifunctional or higher functional crosslinkable functional group, and the low-density crosslinking component (B) has a reactivity of 1.0 mmol / g or less. The active energy ray-curable resin composition according to claim 1, which is a reactive resin component having: 3. The high-density crosslinking component (A) and the low-density crosslinking component (B) are acrylate resins.
The active energy ray-curable resin composition described. 4. The active energy ray curable resin composition according to claim 2, wherein the high-density crosslinking component (A) is a polyester acrylate. 5. The active energy ray curable resin composition according to claim 2, wherein the low density crosslinking component (B) is polyurethane acrylate. 6. The active energy ray curable resin composition according to claim 2, wherein the high-density crosslinking component (A) is a polyester acrylate and the low-density crosslinking component (B) is a polyurethane acrylate. Stuff. 7. The high-density crosslinking component (A) is a polyfunctional acrylate having a trifunctional or higher functional group, and the molecular weight per acryloyl group is 500 or less. An active energy ray-curable resin cured product according to any one of the above. 8. The high-density crosslinking component (A) is a polyester acrylate having at least three or more functional groups, which is obtained by reacting a cyclic ester compound, (meth) acrylic acid, and a trifunctional or higher functional polyol. The active energy ray-curable resin composition according to claim 2. 9. The high-density crosslinking component (A) has a molecular weight of 800.
10. The active energy ray-curable resin composition according to claim 8, which is a polyester acrylate of 3 to 3000. 10. The active energy ray curable resin composition according to claim 8, wherein the cyclic ester compound is ε-caprolactone. 11. The active energy ray curable resin composition according to claim 8, wherein the trifunctional or higher functional polyol is dipentaerythritol. 12. The low-density crosslinking component (B) has a molecular weight of 30.
The active energy ray curable resin composition according to claim 2, which is a linear polyurethane acrylate of 00 to 30,000. 13. The low-density cross-linking component (B), a linear polyurethane acrylate, is used as an isocyanate component
The active energy ray-curable type according to claim 2, wherein 4'-dicyclohexylmethane diisocyanate is a polyurethane acrylate in which polyester polyol and / or polycarbonate carbonate is an essential constituent component of the polyol component. Resin composition. 14. The method according to claim 2, wherein the high-density crosslinking component (A) and the low-density crosslinking component (B) are contained in a ratio of 9/1 to 1/9. Active energy ray curable resin composition. 15. The active energy ray-curable resin composition according to any one of claims 1 to 14 is applied to an object, and then 50 ° C. or higher, and the decomposition temperature of the active energy ray-curable resin composition. After being heat-treated at the following temperature, the curable resin composition is cured by irradiation with active energy rays, the active energy ray resin having a component gradient structure of a curing component in the depth direction from the surface of the cured resin. A method for producing a cured product. 16. The activity according to claim 15, wherein the surface temperature of the coating film is maintained at a temperature of 40 ° C. or higher and a decomposition temperature of the active energy ray-curable resin composition or lower during irradiation with active energy rays. Method for producing cured energy ray resin. 17. The method for producing a cured product of active energy ray resin according to claim 15, wherein the irradiation with active energy ray is carried out in an inert gas atmosphere. 18. The method for producing a cured product of active energy ray resin according to claim 15, wherein the active energy ray is an ultraviolet ray or an electron beam. 19. The active energy ray is an ultraviolet ray,
16. The method for producing a cured product of active energy ray resin according to claim 15, wherein the irradiation with active energy ray is performed in an inert gas atmosphere. 20. At least two resin components, a high-density cross-linking component (A) and a low-density cross-linking component (B), are used as essential resin constituent components and cured by a measurement method by X-ray photoelectron spectroscopy (ESCA). From the surface of the object to a depth of 100 angstroms, the high-density cross-linking component (A) was present in excess of the composition ratio (A) / (B) of the resin composition before curing, and was cured by active energy rays. A resin cured product having a component gradient structure. 21. An infrared total reflection absorption spectrum (ATR-I) comprising at least two resin components, a high-density crosslinking component (A) and a low-density crosslinking component (B), as essential resin components.
According to the measurement method according to R), the high-density cross-linking component (A) exists in a depth of up to 3 microns from the surface of the cured product, exceeding the composition ratio (A) / (B) of the resin composition before curing. , A resin cured product having a component gradient structure that is cured by active energy rays. 22. At least two resin components, a high-density cross-linking component (A) and a low-density cross-linking component (B), are used as essential resin constituent components and cured by a measurement method by X-ray photoelectron spectroscopy (ESCA). The content ratio (A) / (B) of the high-density crosslinking component (A) and the low-density crosslinking component (B) at a depth of 100 angstroms from the surface of the product is (A) /
Exists in excess of the composition ratio of (B), and (A) /
The composition ratio of (B) is the infrared total reflection absorption spectrum (AT
R-IR) is a composition gradient structure cured by active energy rays, which is higher than the composition ratio of (A) / (B) at a depth of 3 microns from the surface of the cured product. A cured resin product. 23. The surface of the cured product produced by the production method according to any one of claims 15 to 19 has stain resistance and solvent resistance, and the elongation at break is 80% or more. 21. A cured resin product cured by active energy rays having a component gradient structure according to claim 20. 24. The surface of a cured product produced by the production method according to any one of claims 15 to 19 has stain resistance, solvent resistance, and a breaking elongation of 80% or more. 22. A resin cured product cured by active energy rays having a component gradient structure according to claim 21. 25. The surface of the cured product produced by the production method according to any one of claims 15 to 19 has stain resistance and solvent resistance, and the elongation at break is 80% or more. 23. A cured resin product cured by active energy rays having a component gradient structure according to claim 22.