JP2001240739A - Resin composition for offset printing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition for a highly fine offset printing material which shows excellence in weather resistance and discoloration, practical durability and productivity. SOLUTION: A resin composition for an offset printing material contains an emulsion having an average particle diameter of not more than 3.0 μm of a polyurethane resin which contains a polycarbonate chain or a polycarbonate chain and a polyester chain in a molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a resin composition for offset printing materials, and has excellent suitability for offset printing.
The present invention relates to an offset printing material that has low curl, high productivity, and can perform high-density recording and printing with an offset printing machine.

[0002]

2. Description of the Related Art In recent years, in particular, the demand for ink jet printers for full color has been increasing. However, when printing on a porous support such as paper or a fiber sheet or a non-porous support such as a film, For the purpose of imparting high-definition printability and ink bleeding, a porous support is treated with a special agent before use.

[0003] As a porous support treated with a special agent, for example, an ink jet paper produced by a method of applying a mixed liquid of various hydrophilic resins and silica (Japanese Patent Laid-Open No. 59-1).
48583, 55-51583, 58-7
No. 2495) and an ink jet paper using a urea-formalin resin (Japanese Patent Application Laid-Open No. 58-72495).

[0004] These agents have been devised so as to have relatively good ink absorbency and to reduce the spread of ink. However, water resistance is not sufficiently considered, and there is a disadvantage that water resistance is poor.

Next, a method using a basic latex (JP-A-57-36692) has been proposed to prevent information recorded by an ink jet from being erased by water or various chemicals. However, this technique is not yet satisfactory, and this technique uses a cationic resin, which is difficult to use together with an anionic resin. There is a problem that a dedicated line is required.

On the other hand, proposals have been made to improve the suitability for printing by making the coating layer a multilayer structure (Japanese Patent Application Laid-Open Nos. 61-35275 and 5-85034). However, these techniques cannot be used for printing other than ink jet, and when used for purposes other than ink jet, other methods must be used. When these methods are employed, there is a concern that the process is complicated.

In the ink jet recording material manufactured by the above-mentioned conventional technique, since the ink jet ink is a special water-based type, the recording material is used for other uses, for example, an offset printing machine and a thermal transfer printer. Can not be used in many cases. Offset printing is capable of multicolor printing, and about 90% of the general-purpose systems are used in Japan. On the other hand, the laser method and the thermal transfer printer are one of the methods most suitable for other full-color printing systems together with the ink jet printer.

At present, the demand for colorization of recording materials has been increasing in recent years, and in order to express satisfactory performance in each system, it is presently necessary to prepare dedicated recording materials for printing machines and printers.

Under these circumstances, a multi-purpose recording material which is a recording material for an ink jet and can be used in another printing system is required from a user's standpoint. There is a demand for a recording material that can be applied to various porous substrates (paper, spunbond, NWF, etc.) at the same time as having a simple process in production.

[0010] In addition, there is known a technique in which the ink jet printability is extremely excellent by using boehmite and a water-soluble resin, but it is not satisfactory in gloss and transparency, and water resistance and dryness are poor. High speed printing still needs improvement.

Recently, the market has demanded a recording material having particularly high gloss and high transparency, but a material which is totally satisfactory has not yet been obtained. A series of ink jet recording materials using a urethane resin have been proposed. That is, Japanese Patent Publication No. 3-42590 proposes an ink jet recording material containing a reaction product of an isocyanate compound and a polyether polyol. This technique is a method of producing a recording material by applying a mixture of an isocyanate compound and a polyether polyol to a film or the like and reacting the mixture on the coated surface.

However, when a polyether polyol is used as a raw material, heat resistance yellowing of the film, weather resistance, etc.
When used outdoors, there is a disadvantage in quality. Attempts have been made to eliminate these disadvantages with additives, but to a less than satisfactory level. In addition, there is also a disadvantage that the ink absorbability that can withstand high-speed printing is poor, and it is difficult to form a transparent and glossy film. Furthermore, the formation of a film by reacting an isocyanate and a polyol requires aging over a long period of time to obtain a film of a practical level, and if the reaction is not completed, the coated sheet is taken off. In this case, there is also a disadvantage that the blocking property under high temperature and high pressure and the gloss smoothness, which are supposed to be deteriorated, that is, the problem of so-called quality variation easily occur.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-definition resin composition for offset printing materials which has improved weather resistance and discoloration and has practical levels of durability and productivity. I do.

[0014]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventor has found that a specific polyurethane resin emulsion, and further a water-soluble epoxy compound and / or a water-soluble epoxy compound.
Or using acetoacetylated polyvinyl alcohol in combination,
Furthermore, they have found that the conventional problems can be solved by using an epichlorohydrin polyamide resin in combination, and have completed the present invention.

That is, the present invention is a resin composition for an offset printing material, comprising a polyurethane resin emulsion having a polycarbonate chain or a polycarbonate chain and a polyester chain in a molecule and having a particle diameter of 3.0 μm, and is preferably Is obtained by reacting a polyurethane resin of a polyurethane resin emulsion with a polyol containing a polycarbonate polyol or a polycarbonate polyol and a polyester polyol and an aliphatic isocyanate compound, and preferably the polyurethane resin of the polyurethane resin emulsion has a sulfonic acid group in a molecule. Polyurethane resin, preferably further comprising an epichlorohydrin polyamide resin, preferably further comprising a water-soluble epoxy compound and / or acetoacetylated vinyl About offset printing material for the resin composition comprising alcohol.

Further, when an epichlorohydrin polyamide resin is contained, the proportion thereof is from 5:95 in terms of solid content weight ratio.
The present invention relates to a resin composition for an offset printing material having a ratio of 95: 5. In the present invention, the epichlorohydrin polyamide resin is a cationic resin, and this resin and a specific polyurethane resin emulsion are stably present in water, and
When this composition is formed into a film, there is an effect that an ultrafine porous film which does not impair the transparency can be formed, and the above-mentioned problem has been solved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail. The polyurethane resin emulsion containing a polycarbonate chain in a molecule of the present invention and having a particle diameter of 3.0 μm can be produced by a known production method. That is, specifically, for example, a polyol containing a polycarbonate chain (hereinafter referred to as a polycarbonate polyol)
And diisocyanate in a solvent, followed by emulsion formation.

Since an aqueous dispersion in which the diisocyanate and the polycarbonate polyol have a high molecular weight in advance and the diisocyanate has no reactivity is applied, aging for forming a practical film is unnecessary, and There is no variation at all, and productivity can be improved.

Examples of the polycarbonate polyol include compounds obtained by reacting glycols such as 1,4-butanediol, 1,6-hexanediol, diethylene glycol and the like with diphenyl carbonate and phosgene. These can be used alone or in combination of two or more.

As the diisocyanate, for example, 2,4
-Tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3 '-Dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6- Hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,
4-cyclohexylene diisocyanate, xylylene diisocyanate, tetramethylene xylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,
4'-dicyclohexylmethane diisocyanate, 3,
3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate and the like can be mentioned, and each can be used alone or in combination of two or more.

Among these diisocyanates, aliphatic diisocyanates are preferred from the viewpoints of stability and light resistance. As the aliphatic diisocyanate, among the diisocyanates listed above, those belonging to the aliphatic diisocyanate can be used as they are.

In practicing the present invention, commercially available polyurethane resin emulsions having polycarbonate chains can be used. In use, it is necessary to select an emulsifier having as small an amount as possible from the viewpoint of film strength and water resistance.

The average particle size of the polyurethane resin in the polyurethane resin emulsion must be not more than 3.0 μm from the viewpoint of transparency, stability and water resistance of the resin emulsion. If the particle size exceeds 3.0 microns, the water resistance, stability, transparency, print gloss and the like will be inferior to practical levels, which is not preferable.

Commercially available polyurethane resin emulsions of the present invention containing polycarbonate chains in the molecule and having a particle size of 3.0 μm include, for example, “Bondick” (trade name, manufactured by Dainippon Ink and Chemicals, Inc.). ), "Hydran" (trade name) and "Impraniel" manufactured by Bayer AG
(Product name) and the like.

The polyurethane resin emulsion of the present invention containing a polycarbonate chain and a polyester chain in a molecule and having a particle size of 3.0 μm can be produced by a known production method. That is, specifically, for example, a polycarbonate polyol, a polyol having a polyester chain (hereinafter, referred to as polyester polyol) is reacted with a diisocyanate in a solvent and then produced by emulsification, or the polycarbonate polyol and the diisocyanate are dissolved in a solvent. In the reaction, after that, the emulsion was reacted with a polyester polyol and diisocyanate in a solvent,
It can be produced by mixing with an emulsion.

As the polycarbonate polyol and the diisocyanate, the compounds mentioned above can be used as they are. As the polyester polyol, for example, ethylene glycol, propylene glycol, 1,3-
Propanediol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,
Glycol components such as 4-cyclohexanediol, 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone and their alkylene oxide adducts, and succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, Maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-
Naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid,
Biphenyl dicarboxylic acid, 1,2-bis (phenoxy)
Ethane-p, p'-dicarboxylic acid and anhydride or ester-forming derivatives of these dicarboxylic acids; p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid, and ester-forming derivatives of these hydroxycarboxylic acids And a polyester obtained by a ring-opening polymerization reaction of a cyclic ester compound such as e-caprolactone, and a copolymerized polyester thereof.

In addition to the above-mentioned polycarbonate polyols and polyester polyols, other polyols can be used. As polyols other than the above,
For example, there is a polyol having an alkylene oxide chain. Representative examples of the alkylene oxide chain include ethylene oxide, propylene oxide, and ethylene oxide adducts of bisphenol, and these may be used alone or in combination of two or more. Although there is no particular limitation on the content of the alkylene oxide chain, the mechanical strength of the film is generally at a practical level when used in combination with another polyol component.

The polyurethane resin of the polyurethane resin emulsion of the present invention is preferably a polyurethane resin having a sulfonic acid group in the molecule. A polyurethane resin emulsion having a sulfonic acid group can be obtained by using a diol, a diamine, a diisocyanate, or the like having a sulfonic acid group at the time of reacting a polycarbonate polyol with a diisocyanate. Usually, it can be introduced in the form of diamine or diol by increasing the molecular weight of the prepolymer having a terminal isocyanate (chain elongation step). Generally, it often has a carboxylic acid group, but in the case of the present invention, the use of a sulfonic acid group type is preferred in terms of curling properties of the coated sheet. In general, a type containing a large amount of carboxylic acid groups is liable to curl. In the case of the present invention, a small amount of a carboxylic acid group may be used in combination with a sulfonic acid group.

On the other hand, improvements in weather resistance, discoloration, ink absorption, gloss, transparency, and productivity, which are problems in the reaction products of polyether polyols and isocyanates, which have been conventionally used, have been improved by polycarbonate. A stable composition can be obtained without gelation by adding a polyamide epichlorohydrin resin to an aqueous dispersion urethane emulsion having a chain. This is probably due to the formation of fine structures resulting from ionic microaggregation of cations and anions. Furthermore, by blending a water-soluble epoxy compound and / or acetoacetylated polyvinyl alcohol, the durability of the substrate can be further improved when it is applied to various substrates.

The epichlorohydrin polyamide resin of the present invention is generally known as a paper strength enhancer. This resin can be produced by a known method, for example, obtained by dehydration polycondensation of adipic acid and diethylenetriamine. As a commercial product of this resin, Japan PMC
"WS525", "WS535" and "WS57"
0 "and the like.

The amount of the epichlorohydrin polyamide resin used is such that the polyurethane resin emulsion and the epichlorohydrin polyamide resin are in a weight ratio of from 5:95 in terms of solid content.
95: 5. If the amount of epichlorohydrin polyamide is less than 5% by weight, printability is poor. On the other hand, if it exceeds 95% by weight, there is a problem in work due to the adhesiveness of the film.

The epichlorohydrin polyamide resin is a cationic resin, but is generally immiscible with an anionic polyurethane resin emulsion. When a specific polyurethane resin emulsion is used, it can be stably dispersed in water without forming an agglomerate with the cationic resin, and both printability and glossiness can be achieved. Although the details of the reason are not clear, it is presumed that ultra-micro agglomeration of cations and anions (a level that does not affect glossiness and transparency) is formed and printability is improved.

That is, by using a specific polyurethane resin emulsion having an average particle size of 3.0 μm or less containing a polycarbonate chain or a polycarbonate chain and a polyester chain as the polyurethane resin emulsion, the emulsion is stably present in an emulsion state with the cationic resin. (Emulsions that are not stable as a mixture of cations and anions do not give satisfactory results in printability), and the dried film forms a transparent and printable microporous material. It is considered that the effect of the above is obtained. Only in the form of an aqueous emulsion, micro-aggregation can be formed.

Various types of recording materials using a polyurethane resin have been introduced. According to the present invention, transparency and glossiness that cannot be exhibited only by the reaction product of the above-mentioned conventional isocyanate and polyether polyol alone can be exhibited.

The water-soluble epoxy compound of the present invention includes
For example, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidel tris (2-hydroxyethyl) isocyanurate, glycerol polyglycidyl ether, triglyceride Various types such as methylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether, 1,6 hexanediol diglycidyl ether, ethylene / propylene glycol diglycidyl ether can be used, and preferably a trifunctional or higher sorbitol polyglycidyl ether is used. preferable.

The water-soluble polyepoxy compound of the present invention can be arbitrarily compounded, and the mixing ratio is not particularly limited. 0.1 to 100 parts by weight of the resin composition
-20 parts by weight.

The acetoacetylated polyvinyl alcohol of the present invention generally refers to a product prepared by adding a liquid or gaseous diketene to a solution or powder of a polyvinyl alcohol-based resin. The mixing ratio of the acetoacetylated polyvinyl alcohol is not particularly limited, but is used in an amount of 50 to 500 parts by weight based on 100 parts by weight of the aqueous polyurethane dispersion having a polycarbonate chain.

Commercially available acetoacetylated polyvinyl alcohols include “Gosefimer Z-100” and “Gosefimer Z-20” manufactured by Nippon Synthetic Chemical Co., Ltd.
"0" (both are trade names) and the like, and these can be used.

The combined use of a water-soluble epoxy compound and / or acetoacetylated vinyl alcohol has the effect of improving gloss and durability. In the resin composition for an offset printing material of the present invention, other additives can be blended within a range that does not impair the printability and other printability of offset printing.

As other additives, talc, kaolin,
Examples thereof include calcium carbonate, silicon oxide, and aluminum oxide, which are mixed and dispersed with the above composition. The resin composition for offset printing materials of the present invention is applied to various substrates.

The substrate is mainly paper, paperboard, various films, and the like, and other various fiber substrates such as nonwoven fabric and spun bond. As a method of applying the resin composition for offset printing material of the present invention to a substrate, air knife coating, blade coating, roll coating, gravure coating, impregnation,
Examples include size press coating and gate roll coating.

[0042]

The present invention will be described below with reference to examples. All parts and percentages in the examples are on a weight basis.

Example 1 50 parts of Bondic 2250 [aqueous dispersion of polyurethane having a polycarbonate chain, average particle diameter 0.2 micron, manufactured by Dainippon Ink and Chemicals, Inc.] and WS535
[50 parts of epichlorohydrin polyamide resin manufactured by Nippon PMC Co., Ltd. were blended to obtain a stable composition without gelation. Further, Z200 [acetoacetylated polyvinyl alcohol manufactured by Nippon Synthetic Chemical Co., Ltd.]
0 parts of a resin composition for offset printing materials was obtained.

This composition was applied to an uncoated film (100 μm) with a comma coater at a solid content of 30%.
Drying was performed at a drying temperature of 120 ° C. for 10 seconds to obtain a recording material.
The recording paper obtained was evaluated using an RI printer for checking the suitability for offset printing. The results are shown in Table 1. It can be seen that the printability is excellent.

Example 2 Hydran HW-970 [Dainippon Ink Chemical Industry Co., Ltd.
Polycarbonate Chain-Containing Polyurethane Aqueous Dispersion Containing Sulfonic Acid Groups] as a solid content of 30 parts,
Gosefimer Z-200 [Nippon Gohsei Chemical Co., Ltd.
Acetoacetylated polyvinyl alcohol] was mixed as a solid content in 70 parts and WS535 [Epichlorohydrin polyamide resin manufactured by Nippon PMC Co., Ltd.] in 30 parts to obtain a resin composition for offset printing materials. It was applied to a film (hereinafter referred to as recording material B) and evaluated in the same manner as in Example 1. The results are shown in Table 1. It can be seen that the printing suitability was excellent as in Example 1.

Example 3 To 100 parts of the solid content of stable A obtained in Example 1, 5 parts of a water-soluble epoxy compound CR-5L [manufactured by Dainippon Ink and Chemicals, Inc.] was added as a solid content. Thus, a composition was obtained. It was applied to paper in the same manner as in Example 1 (hereinafter referred to as recording material C) and evaluated. The results are shown in Table 1. It can be seen that the printing suitability was excellent as in Example 1.

Example 4 Hydran HW-930 [manufactured by Dainippon Ink and Chemicals, Inc. Aqueous dispersion of polyurethane having polyester polyol chain and sulfonic acid group, average particle size of 2.0
Micron] and hydran HW970 [aqueous dispersion of polyurethane having a polycarbonate polyol chain manufactured by Dainippon Ink and Chemicals, Inc., average particle size 0.1 micron] in a ratio of 50:50 in terms of solid content. Except that Dick 2250 was used instead of Dick 2250, it was applied to a film in the same manner as in Example 1 (hereinafter referred to as recording material D) and evaluated. The results are shown in Table 1. It can be seen that the printability is excellent.

Example 5 In Example 2, a film was coated with only HW-970 without using WS535 and evaluated (hereinafter referred to as recording material E). The results are shown in Table 1. Although inferior to Example 2, it is at a practical level.

[0049]

[Table 1]

Comparative Example 1 A composition (hereinafter referred to as recording material F) was prepared in the same manner as in Example 2 except that Hydran HW-970 was replaced with Hydran HW-301 [a carboxyl group-containing polyester polyurethane aqueous dispersion manufactured by Dainippon Ink and Chemicals, Inc.]. ), But the mixed solution thickened with time.

Comparative Example 2 In Example 2, the film was coated with only WS535 without using HW-970 and evaluated. The results are shown in Table 2.
It was inferior to Example 2.

[0052]

[Table 2]

[0053]

The recording material using the resin composition for offset printing material of the present invention has excellent offset printability.

Claims (8)

[Claims] 1. A resin composition for an offset printing material comprising a polyurethane resin emulsion containing a polycarbonate chain or a polycarbonate chain and a polyester chain in a molecule and having an average particle size of 3.0 μm or less. 2. The offset printing material according to claim 1, wherein the polyurethane resin of the polyurethane resin emulsion is obtained by reacting a polycarbonate polyol or a polyol containing a polycarbonate polyol and a polyester polyol with an aliphatic isocyanate compound. Resin composition. 3. The resin composition for an offset printing material according to claim 1, wherein the polyurethane resin of the polyurethane resin emulsion has a sulfonic acid group in a molecule. 4. The resin composition for an offset printing material according to claim 1, further comprising an epichlorohydrin polyamide resin. 5. The resin composition for an offset printing material according to claim 4, wherein the ratio of the polyurethane resin emulsion to the epichlorohydrin polyamide resin is from 5:95 to 95: 5 in terms of solid content weight ratio. 6. The resin composition for an offset printing material according to claim 1, further comprising a water-soluble epoxy compound and / or acetoacetylated vinyl alcohol. 7. An offset printing material provided with a coating layer comprising the resin composition for an offset printing material according to claim 1 on a base material. 8. An offset printed matter obtained by performing offset printing on the offset printing material according to claim 7.