JP2013141789A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate for an interior decorative sheet which is a laminate having a three-layered structure composed of a lowest layer, an intermediate layer and a top coat layer formed by curing an ionizing radiation curable resin composition on a base material, and achieves both of conflicting properties of scratch resistance and impact resistance by changing the hardness of a coating film of each layer.SOLUTION: The laminate has a three-layered structure composed of a relatively soft primer layer as a lowest layer, a moderately hard intermediate layer and a hard top coat layer on a base material, and an ionizing radiation curable resin composition as the top coat layer contains an ionizing radiation curable resin and an acrylic polyol so as to achieve both of scratch resistance and impact resistance by making the coating film compositions gradually harder from the primer side near the original sheet.

Description

  The present invention is a laminate having a three-layer structure composed of a bottom layer, an intermediate layer, and a top coat layer obtained by curing an ionizing radiation curable resin composition on a substrate, and the hardness of the coating film of each layer It is related with the laminated body for decorative sheets for interiors in which the performance which contradicts scratch resistance and impact resistance is compatible.

  Cosmetic films for home interior use have a wide variety of design coordination for harmony with interior interiors and storage furniture, and environmental benefits to prevent natural tree depletion. Expect big growth.

  On the other hand, cosmetic films generally have insufficient surface scratch resistance relative to natural wood. Therefore, it is indispensable to improve the pencil hardness, Hoffman scratch and coin scratch required for the top coat agent of the decorative film.

In recent years, the topcoat agent for decorative sheets is shifting from thermosetting resins to ionizing radiation curable resins. The thermosetting resin has good film processability, but there is a tendency that the hardness of the coating film required for performance such as scratch resistance cannot be obtained. On the other hand, if the ionizing radiation curable resin alone is used to increase the crosslink density of the resin and the coating amount of the coating film to form a coating film, hardness can be obtained, but film workability and impact resistance after construction are remarkably inferior.
Furthermore, a method of mixing a thermosetting resin with an ionizing radiation curable resin has been tried, but as a result, a sufficient surface hardness cannot often be obtained. (For example, see Patent Documents 1 to 4).

JP 2000-117925 A JP 2002-028904 A JP 2005-1119022 A JP 2006-076001 A

  An object of the present invention is a laminate having a three-layer structure composed of a bottom layer, an intermediate layer, and a top coat layer obtained by curing an ionizing radiation curable resin composition on a substrate, and a coating film of each layer An object of the present invention is to provide a laminate for a decorative sheet for interior use, which can satisfy both the scratch resistance and impact resistance conflicting properties by changing the hardness.

  The inventors of the present invention provide a laminate having a three-layer structure including a bottom layer, an intermediate layer, and a topcoat layer obtained by curing an ionizing radiation curable resin composition on a substrate, the ionizing radiation curing The present inventors have found a laminate in which a mold resin composition contains an ionizing radiation curable resin and an acrylic polyol, and have reached the present invention.

  That is, according to the present invention, in a laminate having a three-layer structure of a relatively soft primer layer / medium-hard intermediate layer / hard topcoat layer on the lowermost layer on the base material, the coating composition is close to the original fabric. A laminate comprising an ionizing radiation curable resin and an acrylic polyol, the ionizing radiation curable resin composition as the top coat layer, which is gradually hardened from the primer side and has both scratch resistance and impact resistance. I will provide a.

  Coat for decorative sheet used for building interior materials such as floor materials (horizontal materials), face materials (vertical materials), door materials, frame materials, etc. that have both the performance of conflicting scratch resistance and impact resistance. A laminate for an agent can be obtained.

  Next, the coating composition used in the laminate of the present invention will be described.

  The coating composition used in the laminate of the present invention has a relatively soft primer layer / medium-hard intermediate layer / hardest topcoat layer on the base material, which increases adhesion to the base material on the bottom layer. In a laminate with a three-layer structure, the resin composition is gradually hardened from the primer side close to the original fabric, and the film thickness of the intermediate layer and the topcoat layer can be freely changed, so that the scratch resistance and impact resistance can be changed. It is characterized by having compatible physical properties.

  First, the top coat layer that is required to be the hardest of the three layers is formed of a mixture of an ionizing radiation curable resin and an acrylic polyol.

The ionizing radiation curable resin composition in the laminate of the present invention is cured by irradiation with ionizing radiation such as electron beams, ultraviolet rays, or γ rays.
In the case of curing with ultraviolet rays, a known ultraviolet irradiation device equipped with a high pressure mercury lamp, an excimer lamp, a metal halide lamp or the like can be used. The amount of ultraviolet irradiation at the time of curing is preferably 30 to 1000 mJ / cm ² . Curing is insufficient at less than the amount of irradiation is ^{30mJ / cm 2, 1000mJ / cm} 2 by weight, the yellowing of the coating film variable, there is a possibility that damage such as occurs in the substrate due to heat.

  When hardening with an electron beam, a well-known electron beam irradiation apparatus can be used. The amount of electron beam irradiation during curing is preferably 10 to 100 kGy. If the irradiation dose is less than 10 kGy, curing is not sufficient, and if it exceeds 100 kGy, damage to the coating film and the substrate may occur.

  In the case of curing by irradiation with ultraviolet rays, a photo (polymerization) initiator that generates radicals and acids by irradiation with ultraviolet rays is added in an amount of 0.1 to 20 parts per 100 parts by weight of the active energy ray-curable compound. It is preferable to add about part by weight.

  Radical-generating photo (polymerization) initiators include hydrogen abstraction types such as benzyl, benzophenone, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin ethyl ether, diethoxyacetophenone, benzylmethyl ketal, hydroxy Examples include photocleavage types such as cyclohexyl phenyl ketone and 2-hydroxy-2-methylphenyl ketone. These can be used alone or in combination.

  In the laminate of the present invention, examples of the ionizing radiation curable resin used in the topcoat layer include urethane (meth) acrylates having 2 to 10 functional groups having a weight average molecular weight of 1000 to 15000. If the molecular weight is less than 1000, the flexibility of urethane (meth) acrylate cannot be exhibited sufficiently. On the other hand, when the molecular weight exceeds 15000, properties such as weather resistance and stain resistance are deteriorated. Urethane (meth) acrylate has a weight average molecular weight of 2000 to 5000 and preferably 3 to 6 functional groups. As the diisocyanate of the urethane skeleton of urethane (meth) acrylate, there are a yellowing type and a non-yellowing type. Non-yellowing type aliphatic or cycloaliphatic diisocyanates are preferred because they are used as durable consumer goods. For example, isophorone diisocyanate, 2,2,4 (2,4,4) trimethylhexamethylene diisocyanate, 4,4'dicyclohexylmethane diisocyanate 1,6 hexamethylene diisocyanate and the like.

  In the laminate of the present invention, examples of the thermoplastic resin used in the topcoat layer include general known acrylic polyol resins used in inks and paints having a glass transition temperature in the range of 70 ° C to 150 ° C. It is done. When the glass transition temperature is 70 ° C. or lower, the scratch resistance is lowered. The glass transition temperature is desirably 80 to 105 ° C.

  In order to increase the scratch resistance of the ionizing radiation curable resin alone, a method of increasing the crosslink density of the resin and the coating amount of the coating film can be considered, but in that case, the impact resistance is remarkably lowered. Therefore, ionizing radiation curable resin and thermosetting resin are used to modify from a hard and brittle coating film of ionizing radiation curable resin alone to a tough coating film by hybridization using a blend of ionizing radiation curable resin and thermosetting resin. The mixing ratio of the acrylic polyol is 80:20 to 50:50 by weight, and more preferably 70:30 to 60:40.

  First, the top coat layer required to be the hardest among the three layers of the laminate of the present invention is a mixture of an ionizing radiation curable resin and an acrylic polyol resin, and the content thereof is 80% by weight. It is 20-50: 50, More preferably, it contains 70: 30-60: 40.

  A curing agent can also be used in the mixture of the above-mentioned ionizing radiation curable resin and acrylic polyol resin. For example, when isocyanate is added as a curing agent, the crack resistance, stain resistance, and solvent resistance of the coating film surface are further improved. Usable isocyanates include 1,6-hexamethylene diisocyanate (HDI), 2,2,4 (2,4,4) -trimethylhexamethylene diisocyanate (TMDI), 4,4'-dicyclohexylmethane diisocyanate (HMDI). ), 1,4 cyclohexyl diisocyanate (CHDI), isophorone diisocyanate (IPDI), lysine diisocyanate (LDI), hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate and the like. The isocyanate may be an adduct or multimer of the above isocyanate. In addition, polyisocyanates such as derivatives (adducts) obtained by adding these isocyanates to polyols may be used. Moreover, although the weight solid content ratio of the mixture of the above-mentioned ionizing radiation curable resin and acrylic polyol resin and isocyanate is not limited, the amount of isocyanate is 5 with respect to 100 parts by weight of the mixture of ionizing radiation curable resin and acrylic polyol resin. It is -40 weight part, Preferably it is 10-20 weight part, More preferably, it contains 10-15 weight part.

  A matting agent for adjusting the gloss of the coating film surface can also be used in the above-mentioned mixture of ionizing radiation curable resin and acrylic polyol. Examples of the matting agent include silica, resin beads, and glass beads. Among them, silica is preferable. Further, the weight-solid content ratio of the above-mentioned mixture of ionizing radiation curable resin and acrylic polyol and silica is not limited because it depends on the required gloss value as a decorative film for end use, but the mixture of ionizing radiation curable resin and acrylic polyol. Silica is 5 to 40 parts by weight, preferably 6 to 25 parts by weight, more preferably 8 to 16 parts by weight with respect to 100 parts.

  Next, an intermediate layer located between the top coat layer and the lowermost layer and being medium-hard is formed of a mixture of an acrylic polyol resin and a urethane resin. This acrylic polyol resin may be the same as the acrylic polyol resin used for the top coat layer described above.

Examples of the urethane component polyol used in the intermediate layer include, but are not limited to, polyester polyols, polyether polyols, and polycarbonate polyols. Among these polyols, polyester oliol is preferable when importance is attached to the balance of weather resistance, adhesion, and cost merit.
The mixture of acrylic polyol resin and urethane resin is 80:20 to 20:80 by weight ratio, more preferably 70:30 to 30:70.

In the coating composition used as an intermediate | middle layer, it is essential to contain the isocyanate used as a hardening | curing agent. This isocyanate may be the same as the isocyanate used for the top coat layer described above. The reason for adding isocyanate is necessary for improving adhesion with the topcoat layer and improving solvent resistance.
Isocyanate is 10-70 weight part with respect to 100 weight part of mixture of the above-mentioned acrylic polyol resin and urethane resin, More preferably, it contains 20-60 weight part.

  As with the top coat layer, for example, when silica is added as a matting agent, it is possible to finely adjust the gloss of the coating surface. Silica is 10 to 30 parts by weight, more preferably 10 to 25 parts by weight, based on 100 parts by weight of the mixture of acrylic polyol resin and urethane resin.

Next, the lowermost layer provided for the purpose of improving the adhesion to various base materials is formed of a mixture of an acrylic polyol resin and a urethane resin, like the above-described intermediate layer. Both the acrylic polyol resin and the urethane resin may be the same as the acrylic polyol resin and the urethane resin used in the above-described intermediate layer coating composition.
The lowermost layer has a content of acrylic polyol resin and urethane resin of 50:50 to 10:90, preferably 40:60, in a weight percent ratio so as to be a relatively flexible primer layer to be directly applied to the substrate. ~ 30: 70.

In the coating composition used as the lowest layer, it is essential to contain the isocyanate used as a hardening | curing agent similarly to an intermediate | middle layer. This isocyanate may be the same as the isocyanate used for the above-mentioned topcoat layer or intermediate layer.
Isocyanate is 10-70 weight part with respect to 100 weight part of mixture of the above-mentioned acrylic polyol resin and urethane resin, More preferably, it contains 20-60 weight part.

  Similar to the top coat layer and the intermediate layer, for example, when silica is added as a matting agent, fine gloss adjustment of the coating film surface becomes possible. Silica is 5 to 40 parts by weight, more preferably 10 to 25 parts by weight, based on 100 parts by weight of the mixture of the acrylic polyol resin and the urethane resin.

  In order to impart various functions to the laminate of the present invention thus obtained, if necessary, within a range not departing from the object of the present invention, a colorant, extender pigment, silicone, lubricant, plasticizer Additives such as antifoaming agents, antioxidants, ultraviolet absorbers, light stabilizers, coupling agents, surfactants, organic solvents and chelating agents, inorganic fillers, and organic fillers can be added.

  There is no particular limitation as a substrate to be a target of the coating composition used in the laminate of the present invention, for example, paper, metal, cloth, olefin film, polyester resin, acrylic resin, vinyl chloride resin, vinylidene chloride resin, polyvinyl alcohol, Polyethylene, polypropylene, polyacrylonitrile, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, ethylene methacrylic acid copolymer, nylon, polylactic acid, polycarbonate film or sheet, cellophane, aluminum foil, etc. The various base materials which can be mentioned can be mentioned.

  As a coating method of the coating composition of the laminate of the present invention, offset printing, flexographic printing, roll coating, reverse roll coating, gravure coating, gravure reverse coating, spinner coating, kiss coating, wheeler coating, dip coating, and silk screen are used. A solid coat, a wire bar coat, a flow coat, a comma coat, a flow coat, a brush coat, a spray coat, and the like can be mentioned, and a gravure reverse coat is preferred.

  Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

(Lower layer / intermediate layer / top coat layer)
<Example 1>
The lowermost layer is a mixture of acrylic polyol (QT510-15ED Tg 102 ° C, hydroxyl value 10, weight average molecular weight 65000, manufactured by Taisei Fine Chemical Co., Ltd.) and polyester urethane (Bernock L7-652, manufactured by DIC) so as to have a solid content ratio of 40/60. An isocyanate (FG 700 hardener made by DIC Graphics) was added to a solid content ratio of 30%, and silica (Fuji Silysia Chemical, Silicia 350) was added so as to have a solid content ratio of 18%.
The intermediate layer is prepared by mixing acrylic polyol (QT510-15ED Tg 102 ° C, hydroxyl value 10 weight average molecular weight 65,000, manufactured by Taisei Fine Chemical Co., Ltd.) and polyester urethane (Bernock L7-652 manufactured by DIC) so as to have a solid content ratio of 50/50, and further isocyanate. (DIC graphics FG700 curing agent) was added to a solid content ratio of 30%, and silica (Fuji Silysia Chemical's Silicia 350) was added to a solid content ratio of 18%.
The top coat layer is a mixture of urethane acrylate (Nihon Gosei Violet UV 7630B: weight average molecular weight 2200, functional group number 6) and acrylic polyol (Arit QT510-15ED Tg 102 ° C., Taisei Fine Chemical Co., Ltd.) in a solid content ratio of 70/30, Further, an isocyanate (FG700 curing agent manufactured by DIC Graphics) was added at a solid content ratio of 7.5%, and silica (Nipgel G-0105 manufactured by Tosoh Silica) was added at a solid content ratio of 8%.

<Example 2>
The lowermost layer and the intermediate layer are the same as those in Example 1, and the top coat layer is made of urethane acrylate (purchased by Nihon Gosei, UV7630B) and acrylic polyol (Arit QT510-15ED Tg102 ° C., manufactured by Taisei Fine Chemical Co., Ltd.) at a solid content ratio of 70/30. The mixture was used.

<Comparative Example 1>
The top coat layer is a mixture of urethane acrylate (Nihon Gosei's purple light UV7630B) and acrylic polyol (Taisei Fine Chemical's Acryt QT510-15ED Tg102 ° C) in a solid content ratio of 90/10, and further isocyanate (DIC Graphics FG700 cured) The mixture was made in the same manner as in Example 1 except that the agent was added with a solid content ratio of 7.5%.

<Comparative example 2>
The top coat layer is a mixture of urethane acrylate (purchased by Nihon Gosei Co., Ltd., purple light UV7630B) and acrylic polyol (Acrit 6AN-493 Tg 70 ° C, manufactured by Taisei Fine Chemical Co., Ltd.) so as to have a solid content ratio of 70/30. The mixture was made in the same manner as in Example 1 except that the agent was added with a solid content ratio of 7.5%.

<Comparative Example 3>
The intermediate layer is a mixture of acrylic polyol (Acrit QT510-15ED manufactured by Taisei Fine Chemical Co., Ltd.) and polyester urethane (Nobach L7-652 manufactured by DIC) at a solid content ratio of 20/80, and further isocyanate (FG700 manufactured by DIC Graphics). The curing agent was mixed in the same manner as in Example 1 except that a solid content ratio of 30% and silica (Silicia 350 manufactured by Fuji Silysia Chemical Co., Ltd.) were added so that the solid content ratio was 18%.

(Laminate coating and drying)
In each of Examples 1 and 2 and Comparative Examples 1 to 3, the corona-treated olefin film was coated with a bar coater at the bottom layer primer of 5 g / m ² , the intermediate layer at 8 g / m ² , and the top coat at 13 g / m ² . After coating, it was cured with an electron beam (acceleration voltage 125 kv-50 kGry) and cured in a 60 ° C. oven for 24 hours. The prepared laminate film was bonded to a base material MDF (medium density fiberboard, hot-press molded board obtained by mixing wood pulp with an adhesive (resin)) to prepare an evaluation decorative plate.

(Evaluation method 1: pencil hardness)
Using a pencil hardness tester (manufactured by Toyo Seiki Co., Ltd.), an evaluation is performed using a load of 750 g and a Mitsubishi pencil Hi-UNI, and the hardness of the pencil when the coating film surface is torn and whitened is described.

(Valence method 2: weight whitening resistance)
Using a Hoffman scratch tester (BYK Gardner), the load is applied in increments of 100 g to 300 g, and the load when the coating surface is whitened by tearing is described.

(Value method 3: Coin scratching)
Using a coins scratch tester, apply 10-yen cure to the test piece, add a weight from 5 kg to 5 kg, and increase the load until a continuous flaw occurs on the coating surface. Indicate the load when

(Evaluation method 4: Impact resistance)
Using a DuPont impact tester (manufactured by Toyo Seiki Co., Ltd.), the crack of the coating film is visually observed when the load is dropped from a 1/2 inch impact indenter, a load of 500 g, and a height of 50 cm. The test is performed at N = 5, and the number of times of not cracking is counted.
○: It was not broken 5 times
Δ: not cracked 2 to 3 times
X: All 5 times

    Table 1 shows the evaluation results of the decorative plate sheets described in Examples 1 and 2 and Comparative Examples 1 to 3.

  The laminate of the present invention is suitably used as a cosmetic heat using paper, film, plastic, cloth, metal or the like as a base material. This decorative sheet is used on the surface of articles such as building flooring materials, interior materials and furniture.

Claims (5)

  On a substrate, a laminate of a three-layer structure composed of a bottom layer, an intermediate layer, and a topcoat layer obtained by curing an ionizing radiation curable resin composition, wherein the ionizing radiation curable resin composition is A laminate comprising an ionizing radiation curable resin and an acrylic polyol.   2. The laminate according to claim 1, wherein a mixing ratio of the ionizing radiation curable resin and the acrylic polyol in the ionizing radiation curable resin composition is 80/20 to 50/50 (weight ratio).   The intermediate layer is a composition containing an acrylic polyol, a urethane resin, and an isocyanate compound, and the mixing ratio of the acrylic polyol and the urethane resin in the composition is 80/20 to 20/80 (weight ratio). 2. The laminate according to claim 1.   The lowermost layer is a composition containing an acrylic polyol, a urethane resin, and an isocyanate compound, and the mixing ratio of the acrylic polyol and the urethane resin in the composition is 50/50 to 10/90 (weight ratio). 2. The laminate according to claim 1.   The ionizing radiation curable tree is a non-yellowing urethane acrylate having a weight average molecular weight of 1,000 to 15,000 and an average number of functional groups of 2 to 10, and the glass transition temperature of acrylic polyol in the ionizing radiation curable resin composition ( Tg) is 80 degreeC or more, The laminated body as described in any one of Claims 1-4.