JPH064042U - Flexible printing sheet - Google Patents

Abstract

(57) [Summary] [Purpose] A soft printing sheet made of a polyolefin resin, which has excellent adhesion to the coating film of printing ink, and an antistatic property in which a specific antistatic agent is added in a certain proportion. A flexible printing sheet is provided. [Structure] CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H, CH ₃ R ₂ is an alkyl group> Corona discharge treatment is applied to the surface of the sheet body 1 so that the wet surface tension is about 44 to 54 dyn / cm.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention provides an olefinic soft sheet having excellent physical properties and coating film adhesion of a printing ink, and an ethylene-based copolymer resin composition having a specific polar group and a specific antistatic material. The present invention relates to an olefin-based soft sheet having excellent printability, which is obtained by subjecting a sheet-like material obtained by heating and kneading a resin composition obtained by adding a certain proportion of the above to corona discharge treatment.

[0002]

[Prior art]

 Soft sheets made of olefinic resins such as low density polyethylene are excellent in chemical resistance and mechanical properties, and they are also inexpensive, but one of the drawbacks is that polar groups or reaction in the molecular structure of the resin Since it does not have active groups having properties and has poor solubility in solvents, it is a problem in secondary processing such as printing. Therefore, in order to improve the coating adhesion of the printing ink, it is necessary to perform some treatment on the surface of the sheet to increase the affinity for the ink. As a specific surface treatment method, there is a method of increasing the affinity of the surface with ultraviolet rays, corona discharge, plasma discharge, oxygen, ozone, etc., or a method of roughening the surface with sandplast etc. Of these, activation of the surface by corona discharge treatment is common.

[0003]

[Problems to be solved by the device]

 However, when the corona discharge treatment is performed, there are drawbacks such that the surface activity does not last long enough with respect to changes over time, and the inks used are also limited. In particular, for UV-curable inks used in offset printing and the like, it is not sufficient to provide ink coating adhesion only by surface treatment by corona discharge treatment.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a soft sheet made of a polyolefin resin, which is excellent in coating film adhesion of printing ink. Further, it is to provide a flexible printing sheet excellent in antistatic property, which is obtained by adding a specific antistatic agent at a constant ratio.

[0005]

[Means for Solving the Problems]

To achieve the above object, the technical means of the present invention comprises: CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H, CH ₃ R ₂ is an alkyl group> That is, the sheet body is formed of an ethylene-based copolymer or a mixture thereof, and the surface of the sheet body is subjected to corona discharge treatment.

Further, CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H and CH ₃ R ₂ is an alkyl group> are copolymerized with 100 parts by weight of an ethylene-based copolymer or a mixture thereof. Then

[Chemical 2] 0.01 to 2.0 parts by weight of the monoglyceride-based antistatic agent shown in (3) is added to form the sheet body, and the surface of the sheet body is subjected to corona discharge treatment.

[0007]

【Example】

Hereinafter, an example of the implementation of the flexible printing sheet of the present invention will be described. The flexible sheet A has CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H and CH ₃ R ₂ is an alkyl group>. (Hereinafter referred to as Formula 1) is obtained by subjecting the surface of the sheet body 1 of a desired thickness formed of an ethylene-based copolymer obtained by copolymerization or a mixture thereof to corona discharge treatment (see FIG. 1). ).

Examples of the ethylene-based copolymers include ethylene and various acrylic acid esters such as ethylene methyl methacrylate, ethylene ethyl acrylate, ethylene methyl acrylate, ethylene butyl methacrylate, ethylene hexyl acrylate, ethylene lauryl methacrylate, and ethylene stearyl acrylate, or various acrylic acid esters or the like. It is composed of a seed methacrylic acid ester.

Specifically, for example, the above ethylene-based copolymer or a mixture thereof is used to form a sheet body 1 in a plate shape having a desired thickness by a conventionally known extrusion process, and the corona is formed on the surface of the sheet body 1. Discharge treatment was performed to obtain a flexible printing sheet A. The degree of corona discharge treatment is preferably, for example, JIS K-6768, and the wet surface tension is preferably about 44 to 54 dyn / cm, but is not limited. Therefore, the surface of the soft printing sheet A formed as described above is sufficiently activated, and the ink (UV curable ink) 3 ... Adhesion) is shown in Table 1. The soft printing sheet A had a very soft feeling (flexibility) and a good feeling. In addition, the thickness of the soft printing sheet A is arbitrary in one embodiment, and the sheet form includes a sheet thickness that is generally thicker than a sheet thickness and a sheet thickness (film or the like).

[0010]

[Table 1]

Further, the sheet body 1 constituting the soft printing sheet A of the present invention can be formed into a desired shape by calendering. In this case, an acrylic processing aid, an organic acid metal salt, The organic fatty acid alone or a mixture of two or more kinds thereof is added. The above-mentioned acrylic processing aid, organic acid metal salt, organic fatty acid, or a mixture of two or more thereof, is added in an amount of 0.005 to 10 parts by weight, preferably 0.01 to 3 parts by weight, relative to 100 parts by weight of the resin. Parts by weight. The suitable temperature range when the sheet body 1 is formed by calendering is 100 to 180 ° C, preferably 120 to 170 ° C.

Acrylic processing aids include acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, and other acrylic acid esters, ethyl methacrylate, n-butyl methacrylate. , A group of polymers consisting of copolymers containing methacrylic acid ester such as methacrylic acid-2-ethylhexyl as a main component. Specifically, for example, commercially available Mitsubishi Rayon METABLENE P-700, METABLENE P- 551, Metabrene P-530A, Metabrene L-1000, Kane Ace PA-20, Kane Ace PA-100, Kane Ace PA-100, Asahi Denka Mark LS-3, Mark LS-5 etc.

The organic acid metal salt is a higher fatty acid salt of a metal, such as zinc stearate, zinc laurate, zinc oleate, barium stearate, calcium stearate, dibutyltin laurate, dibutyltin stearate, dibutyltin dilaurate. , Dibutyltin distearate and the like.

The organic fatty acid is, for example, stearic acid, oleic acid, lauric acid, palmitic acid and the like.

The processing aid to be added to the copolymer obtained by copolymerizing the above chemical formula 7 or a mixture thereof may be the above-mentioned acrylic processing aid, organic acid metal salt, organic fatty acid alone or two or more of them. 0.005 to 10 parts by weight is added to 100 parts by weight of the resin. Other additives to this blend are ethylene-vinyl acetate copolymer, ethylene, propylene, butene, butene-butene. Polymers and copolymers such as 1,3-methyl-butene-1, hexene-1, octene-1,4-methyl-pentene-1, etc. as main components, eg high density polyethylene, medium low density polyethylene, ultra low density Other polyolefins consisting of polyethylene, crystalline polypropylene, polybutene, etc. and mixtures thereof, and UV absorbers well known in the technical field of this kind, It is also possible to add antioxidants, pigments, antiblocking agents, and the like.

These formulations depend on the copolymer or their mixture, the type and amount of processing aids added.

A description will be given here of an example of a specific embodiment in the case of calender molding. A mixture of ethylene methyl methacrylate: 100 parts by weight PA-100: 0.5 parts by weight was calendered at a roll temperature of 140 ± 2 ° C. Then, the sheet main body 1 was formed into a plate having a desired thickness, and the surface of the sheet main body 1 was subjected to corona discharge treatment to obtain a soft printing sheet A. The surface of the soft printing sheet A formed as described above was sufficiently activated similarly to the above extrusion molding, and the coating adhesion of the ink (ultraviolet curable ink) 3 was good. Also, the soft printing sheet A had a very soft feeling (flexibility) and a good feeling.

Next, an example of an embodiment of the soft printing sheet A according to claim 2 will be described. An ethylene copolymer obtained by copolymerizing the same formula 1 as described above or a mixture thereof is added to a monoglyceride electrostatic The surface of the sheet body 1 formed by adding the inhibitor 2 is subjected to corona discharge treatment.

The monoglyceride antistatic agent 2 is

[Chemical 3] Which is used alone or as a blend.

The antistatic agent is for preventing process failure due to repulsion of suction due to generation of static electricity in primary processing and secondary processing, failure due to dust absorption, etc. Many monoglyceride type are used. It is generally said that amines have fast-acting properties and fatty acid monoglycerides have long-lasting properties. Usually, these are used by adding them to the olefin resin in an appropriate ratio according to the required performance. The minimum required amount is also added for the purpose of imparting antistatic properties, but due to the compatibility problem with olefin resins, the antistatic agent floats over the sheet surface, which causes the deterioration over time. It is known that the printability deteriorates. The antistatic agent used in the present invention acts very effectively in the blending of the ethylene-based copolymer to maintain the ink adhesion of the molded product over time. it is effective that the C ₁₁ -C _20.

Regarding the decrease in the ink adhesiveness over time, the adhesiveness is sufficiently maintained even after the accelerated test, and the polar group of the ethylene-based copolymer effectively acts. Although there are some unclear points regarding the mechanism of adhesion, the polar groups of the copolymer are dispersed in the surface in a suitable manner, and the surface is in a more activated state than when the corona treatment is applied to a normal resin composition. Regarding the bloom of the antistatic agent, it is considered that the polar group of the copolymer causes the antistatic agent to be uniformly dispersed in the sheet for a long period of time, and a peeling layer is not easily formed on the sheet surface. The function of the antistatic agent is considered to be that the antistatic agent easily exudes to the extent that it has an antistatic effect and that an antistatic agent layer is easily formed on the surface of the sheet.

Regarding the number of carbon atoms of the alkyl group, if the carbon number is C ₁₀ or less, non-uniformity of the ink transfer property is observed, and if it is C ₂₀ or more, the antistatic property and the ink adhesiveness are deteriorated. Considering workability, C _{15 to} C ₁₈ are preferable. Regarding the addition amount, when the amount exceeds 2.0 parts by weight, the adhesion of the ink is deteriorated, while when the amount is less than 0.01 parts by weight, the antistatic property is not sufficient. It is 0.01 to 2.0 parts by weight, preferably 0.03 to 1.0, based on 100 parts by weight of the copolymer or the mixture thereof.

Explaining specific examples, for example, in each ethylene-based copolymer represented by the above formula 1, 100 parts by weight of ethylene methyl methacrylate is added with an appropriate amount of the monoglyceride-based antistatic agent 2 shown in Chemical formula 3 above. Then, the sheet body 1 is formed into a plate having a desired thickness by a conventionally well-known extrusion process, and the surface of the sheet body 1 is subjected to corona discharge treatment (similar to the above, for example, the method of JIS K-6768, the wet surface tension is 44 to 54 dyn / cm) to obtain a flexible printing sheet A. Therefore, Table 2 shows the results of irradiating the ink (ultraviolet curable ink) 3 ... With an RI tester and irradiating it with ultraviolet rays. Further, even the soft printing sheet A had a very soft feeling (flexibility) and a good feeling.

[0024]

[Table 2]

Further, even in the sheet main body 1 that constitutes the soft printing sheet A according to the present invention, calendering can be performed in the same manner as above.

[0026]

[Effect of device]

In the present invention, CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H and CH ₃ R ₂ is an alkyl group> is an ethylene-based copolymer or a mixture thereof. Since the surface of the main body is treated by corona discharge treatment, the flexible printing sheet has excellent coating film adhesion of printing ink compared to the conventional flexible printing sheet made of olefin resin (polyethylene etc.). Was able to provide.

Further, CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H and CH ₃ R ₂ is an alkyl group> are copolymerized with 100 parts by weight of an ethylene-based copolymer or a mixture thereof. Then

[Chemical 4] Since the surface of the sheet body formed by adding 0.01 to 2.0 parts by weight of the monoglyceride type antistatic agent shown in Fig. 1 is treated by corona discharge, the same as the above, compared with the conventional soft type printing sheet, printing is performed. It is possible to provide a flexible printing sheet which has excellent adhesion to the ink coating film and also has excellent antistatic properties, and which can sufficiently maintain the adhesion of the ink coating film.

[Submission date] July 24, 1992

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

[Industrial applications]

The present invention provides an olefinic soft sheet having excellent physical properties and coating film adhesion of a printing ink, and an ethylene-based copolymer resin composition having a specific polar group and a specific antistatic material. The present invention relates to an olefin-based soft sheet having excellent printability, which is obtained by subjecting a sheet-like material obtained by heating and kneading a resin composition obtained by adding a certain proportion of the above to corona discharge treatment. In this specification, Chemical formulas 1 to 4 represent the same formula.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H and CH ₃ R ₂ is an alkyl group> are copolymerized with 100 parts by weight of an ethylene-based copolymer or a mixture thereof. Then

[Chemical 2] 0.01 to 2.0 parts by weight of the monoglyceride-based antistatic agent shown in (3) is added to form the sheet body, and the surface of the sheet body is subjected to corona discharge treatment.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

The processing aid added to the copolymer obtained by copolymerizing the above formula 1 or a mixture thereof may be the above-mentioned acrylic processing aid, organic acid metal salt, organic fatty acid, alone or in combination of two or more thereof. 0.005 to 10 parts by weight is added to 100 parts by weight of the resin. Other additives to this blend are ethylene-vinyl acetate copolymer, ethylene, propylene, butene, butene-butene. Polymers and copolymers such as 1,3-methyl-butene-1, hexene-1, octene-1,4-methyl-pentene-1, etc. as the main component, eg high density polyethylene, medium low density polyethylene, ultra low density Other polyolefins consisting of polyethylene, crystalline polypropylene, polybutene, etc. and mixtures thereof, and UV absorbers well known in the technical field of this kind, It is also possible to add antioxidants, pigments, antiblocking agents, and the like.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

The monoglyceride antistatic material 2 is

[Chemical 3] Which is used alone or as a blend.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

The antistatic agent is for preventing process failure due to repulsion of suction due to generation of static electricity in primary processing and secondary processing, failure due to dust absorption, etc. Many monoglyceride type are used. It is generally said that amines have fast-acting properties and fatty acid monoglycerides have long-lasting properties. Usually, these are used by adding them to the olefin resin at an appropriate ratio according to the required performance. The minimum required amount is also added for the purpose of imparting antistatic properties.However, due to the compatibility problem with olefin resins, the antistatic agent is likely to float due to the bloom phenomenon on the sheet surface. It is known that the printability decreases with time. Antistatic agent used in the present invention, Te formulation smell ethylenic copolymers, so also act very effectively in order to maintain the close contact of the moldings of the ink over time, in monoglyceride system represented by the chemical formula 3 It is effective that the alkyl group (R) has a carbon number (n) of C _{11 to} C ₂₀ .

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

Regarding the carbon number (n ) of the alkyl group (R) , when C ₁₀ or less, non-uniformity of ink transfer property is observed, and when C ₂₀ or more, antistatic property and ink adhesion are deteriorated. To do. Taking workability into consideration, C _{15 to} C ₁₈ are preferable. Regarding the amount of addition, if the amount exceeds 2.0 parts by weight, the adhesion of the ink is deteriorated. On the other hand, if the amount is less than 0.01 parts by weight, the antistatic property is insufficient. The amount is 0.01 to 2.0 parts by weight, preferably 0.03 to 1.0, based on 100 parts by weight of the ethylene copolymer or the mixture thereof.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

Further, CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H and CH ₃ R ₂ is an alkyl group> are copolymerized with 100 parts by weight of an ethylene-based copolymer or a mixture thereof. Then

[Chemical 4] Since the surface of the sheet body formed by adding 0.01 to 2.0 parts by weight of the monoglyceride type antistatic agent shown in Fig. 1 is treated by corona discharge, the same as the above, compared with the conventional soft type printing sheet, printing is performed. It is possible to provide a flexible printing sheet which has excellent adhesion to the ink coating film and also has excellent antistatic properties, and which can sufficiently maintain the adhesion of the ink coating film.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a soft printing sheet according to claim 1.

FIG. 2 is a vertical cross-sectional side view showing an embodiment of the flexible printing sheet according to claim 2;

[Explanation of symbols]

 A: Soft printing sheet 1: Sheet body 2: Antistatic agent 3: UV curable ink

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 24, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Chemical 1] A soft printing sheet obtained by adding 0.01 to 2.0 parts by weight of the monoglyceride-based antistatic agent shown in 1 above to form a sheet body, and subjecting the surface of the sheet body to corona discharge treatment.

Claims (2)

[Scope of utility model registration request] 1. An ethylene-based copolymer obtained by copolymerizing CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H and CH ₃ R ₂ is an alkyl group> or a mixture thereof to form a sheet body. A soft printing sheet formed by corona discharge treatment on the surface of the sheet body. 2. An ethylene copolymer obtained by copolymerizing CH ₂ ═CH ₂ , CH ₂ ═CR ₁ COOR ₂ <R ₁ is H and CH ₃ R ₂ is an alkyl group> or 100 parts by weight of a mixture thereof. , [Chemical 1] A soft printing sheet obtained by adding 0.01 to 2.0 parts by weight of the monoglyceride-based antistatic agent shown in 1 above to form a sheet body, and subjecting the surface of the sheet body to corona discharge treatment.