JPH08118560A - Information carrier sheet - Google Patents

Abstract

PURPOSE: To obtain an information carrier sheet which has excellent balance of adhesive strength and blocking resistance, no influence of oxidative deterioration and excellent printability. CONSTITUTION: A coating layer having adhesive performance at a high pressure and releasing performance in an ordinary state is formed on one side or both sides of a base material sheet. The layer contains (A) a copolymer containing methacrylamide and at least one type or more of vinyl monomer which can be copolymerized with the methacrylamide and (B) a copolymer containing at least one type or more of vinyl monomer having a glass transmission temperature of -70 to 0 deg.C in one particle in such a manner that emulsion polymer (C) in which substantially at least the copolymer (A) is distributed on the surface layer of the particle and the copolymer (B) is distributed therein is used. The solid content ratio by weight of the copolymer (A) and the copolymer (B) is 5/100 to 50100, and the solid content ratio by weight of the methacrylamide in the copolymer (A) is 20 to 80wt.%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an information carrier sheet. More specifically, the present invention relates to a sheet for an information carrier, which is suitable for double-folding or tri-fold postcards and the like, and has excellent confidentiality and is excellent in peeling property and blocking resistance.

[0002]

2. Description of the Related Art In recent years, confidential postcard systems having information hiding properties have begun to spread. Confidentiality is a function that can judge whether or not confidential information has been read by a person other than the addressee.In the beginning, the label is peeled off from the release sheet and adhered on the information to be concealed printed on the postcard. Although the main type is the type that has been used, there are problems that the amount of information that can be hidden is small, that it is difficult to dispose of the release sheet, and that it is costly. Therefore, recently, printing is performed on an information carrier sheet in which the surface of a base sheet such as paper is coated with a peelable adhesive composition,
Confidential postcards of the type in which two or three folds (also called Z folds) are applied after applying high pressure between the rollers of the sealer are increasing, and the attached sheet surface is a finger. Confidentiality is achieved by devising a device that can be easily peeled off with a tape, etc. and cannot be easily re-bonded after peeling.

As described above, it is required that the above-mentioned information carrier sheet used for producing tri-fold and bi-fold postcards is adhered under a high pressure but is releasable and not easily re-adhered after the peeling. However, in addition to this, it is required to have excellent blocking resistance, little deterioration due to oxidation, little ozone deterioration due to ultraviolet irradiation, and excellent printability.

Many proposals for achieving these required performances have been made in the past. For example, Japanese Patent Publication No. 5-5711
No. 7 proposes a pressure-sensitive adhesive printing sheet in which particles having an average particle diameter of 1 to 20 μm and having no thermoplasticity are dispersed in the pressure-sensitive adhesive to form irregularities on the surface of the adhesive to prevent blocking. Further, in JP-A-4-59395,
There is a proposal of an information carrier sheet in which blocking is prevented by providing an adhesive layer composed of a non-peeling adhesive base and fine particles showing non-affinity for the adhesive base on at least a part of the base sheet. . As fine particles used for this,
Often, two or more kinds having different particle sizes are used in combination, and a typical example thereof is a combination of silica and starch.

[0005]

The resin which is the base of the adhesive composition currently used in the above-mentioned information carrier sheet has a lower adhesive property as the glass transition temperature increases, and It is known that the lower the transition temperature, the higher the adhesive performance. When the glass transition temperature is lowered to room temperature or lower to develop the adhesive performance, there are generally those that completely bond with the adhesive alone and those that can be peeled off but easily re-bonded. Confidentiality cannot be obtained.

[0006] A typical information carrier sheet for tri-fold postcards that has been put into practical use is manufactured by applying an adhesive composition in which fine particles are dispersed in an adhesive to a base sheet in order to realize confidentiality. ing. A typical adhesive composition is an adhesive composition composed of latex containing natural rubber as a main component and fine particles. However, since the adhesive composition uses natural rubber, it is easily deteriorated. This deterioration includes deterioration due to oxidation during sheet storage and ozone deterioration caused by UV irradiation during printing with UV curable ink, both of which are considered to be due to unsaturated bonds in natural rubber. Has been. When the adhesive deteriorates, the adhesive strength changes, and excessive deterioration is a fatal defect.

[0007] Further, as disclosed in JP-B-5-57117, by dispersing fine particles having an average particle size of 1 to 20 µm and not having a thermoplasticity in a pressure sensitive adhesive, unevenness is formed on the surface of the adhesive to prevent blocking. In the case of the pressure-sensitive adhesive print sheet which has been prevented, if the average particle size is less than 10 μm, the effect of preventing blocking is small, and if the average particle size is 10 μm or more, the blanket becomes dirty during printing and the print finish becomes poor, which causes a problem. Has become.

The present invention aims to overcome these drawbacks. Specifically, 1) it adheres under high pressure, but it can be peeled and does not easily re-adhere after peeling, 2) it has excellent blocking resistance, 3) it has little deterioration due to oxidation, and 4) ultraviolet rays. An object of the present invention is to obtain an information carrier sheet satisfying the following five items: less ozone deterioration due to irradiation, and 5) excellent printability. At present, there is no known information carrier sheet that satisfies all of the required performances of these five items.

[0009]

Means for Solving the Problems As a result of intensive studies made by the present inventors under an idea completely different from the conventionally known method, 1
Emulsion polymer particles containing a component having an adhesive property in the particles and a component having heat resistance and blocking resistance in a specific ratio are heat resistance, blocking resistance,
They have found that they have excellent adhesiveness and releasability, have little change in characteristics over time, and have excellent printability, and have completed the present invention.

That is, the present invention is a sheet for information carrier, wherein a coating layer having an adhesive property under a high pressure and a peeling property under a normal condition is formed on one side or both sides of a base sheet.
The main component of the coating layer is methacrylamide and a copolymer (A) composed of at least one vinyl monomer copolymerizable with methacrylamide and a glass transition temperature of -70 ° C to 0 ° C. One particle contains at least two copolymers (B) composed of vinyl monomers, and the copolymer (A) is substantially on the surface layer of the particles, and the copolymer (B) is substantially The emulsion polymer (C) particles that are distributed in the interior of the particles are used, and the solid content weight ratio of the copolymer (A) and the copolymer (B) in the emulsion polymer (C) is A: B = 5: 100 to 50:
100, and the solid content weight ratio of methacrylamide in the copolymer (A) is 20 to 80% by weight.
Is a sheet for information carriers.

The base sheet used in the present invention, which may be paper or film, has an information hiding property and therefore has a certain opacity and is good for an adhesive forming a coating layer. Shall have good wetting characteristics. For example, when paper is used as the base sheet, bleached softwood kraft pulp (NBK
P), hardwood bleached kraft pulp (LBKP), softwood bleached sulphite pulp (NBSP), thermomechanical pulp (TMP), and other paper-making pulps. , Sizing agents, retention improvers, drainage improvers, defoamers, dyes, color pigments, fluorescent agents,
Usually, a freeness of 550 to 25 is used in combination with a fixing agent.
0 ml C.I. S. F. Using a well-known paper machine such as a fourdrinier paper machine or a round paper machine. Further, in the present invention, various synthetic resin films or synthetic papers having a certain opacity can be used as the base sheet.

In the emulsion polymer (C) particles used in the present invention, the copolymer (A) exhibits heat resistance, blocking resistance and peelability, and the copolymer (B) exhibits adhesiveness. is there. Then, it is necessary to have a structure in which the copolymer (A) is substantially distributed on the surface layer of the particles and the copolymer (B) is substantially distributed inside the particles. As such a structure, for example, the copolymer (A) is a copolymer (B).
A so-called core-shell structure that covers at least a part of the particles or a structure in which the composition continuously changes from the inside of the particles to the surface layer may be used. In a random copolymer using a vinyl monomer constituting the copolymer (A) and the copolymer (B), or a polymer blend in which the copolymer (A) and the copolymer (B) are simply mixed, Since a structure in which the copolymer (A) is substantially distributed in the surface layer of the particles and the copolymer (B) is substantially distributed inside the particles is not obtained, the emulsion polymer (C) of the present invention is As described above, it is difficult to achieve both heat resistance, blocking resistance, peelability and adhesiveness, and the effects of the present invention are not exhibited.

In producing the emulsion polymer (C), after the copolymer (A) is produced, the vinyl monomer constituting the copolymer (B) is polymerized in an aqueous solution thereof by so-called protective colloid polymerization. Or a known polymerization method using a seed obtained by using the copolymer (B) obtained by emulsion polymerization as a seed and polymerizing the vinyl monomer constituting the copolymer (A) in the presence of the seed. Polymerization by a power feed in which the vinyl monomer constituting the polymer (B) and the vinyl monomer constituting the copolymer (A) continuously change in the particles of the emulsion polymer (C) from the inside to the surface layer. A polymerization method in which the emulsion polymer (C) having a structure in which the copolymer (A) is substantially distributed on the surface layer of the particles and the copolymer (B) is substantially distributed inside the particles can be used. And If not particularly limited.

In the above-mentioned polymerization method, the copolymer (A)
And the solid content weight ratio of the copolymer (B) is A: B = 5: 1.
The range is from 00 to 50: 100, preferably A: B =
7: 100 to 40: 100, more preferably A: B = 1.
It is set to 0: 100 to 30: 100. When the amount of the copolymer (A) is less than 5 parts by weight with respect to 100 parts by weight of the copolymer (B), the adhesiveness is too strong to cause a problem in peelability, and at the same time, the heat resistance and the blocking resistance are poor. . On the other hand, when the amount exceeds 50 parts by weight, the adhesiveness is remarkably deteriorated, and in some cases, the adhesive performance is completely lacking.

Emulsion polymer (C) in the present invention
The copolymer (A) that constitutes the shell of the particles shows that methacrylamide, which is a constituent thereof, has excellent heat resistance and blocking resistance. The solid content weight ratio of methacrylamide in the copolymer (A) is 20 to 80% by weight, preferably 30 to 80% by weight, more preferably 4
It is 0 to 80% by weight. When the amount of methacrylamide used is less than 20% by weight, the heat resistance (printability) during toner fixing of a non-impact printer and the storage of an information carrier sheet after coating with an adhesive, that is, a winding roll. Blocking resistance after production is not obtained in the form of or foam printing paper, and when it exceeds 80% by weight, the viscosity becomes extremely high or, in some cases, aggregates when the emulsion polymer (C) is produced. Such problems may occur.

The glass transition temperature of the copolymer (A) is preferably in the range of 100 ° C to 200 ° C, more preferably 150 ° C to 200 ° C. If the temperature is lower than 100 ° C, the heat resistance and blocking resistance tend to be impaired, and if the temperature exceeds 200 ° C, the coating layer becomes brittle, and at the same time, when an auxiliary material such as clay and calcium carbonate is used, these are added. The tendency of inferior binding property is increased.

Examples of the at least one vinyl monomer copolymerizable with methacrylamide constituting the copolymer (A) include methyl (meth) acrylate, ethyl (meth) acrylate, and (meth). Butyl acrylate, (meth)
2-ethylhexyl acrylate, (meth) acrylic acid 2
-Hydroxyl ethyl, 2-hydroxypropyl (meth) acrylate, 2-aminoethyl (meth) acrylate, 2- (N-methylamino) ethyl (meth) acrylate, 2- (N, N) (meth) acrylate -Dimethylamino) ethyl, glycidyl acrylate (meth), (meth)
2-Methoxyethyl acrylate, (meth) acrylic acid 2
-(Meth) acrylic acid esters such as ethoxyethyl,
Vinyl esters such as vinyl acetate and vinyl propionate, nitrile group-containing monomers such as (meth) acrylonitrile, and carboxyl group-containing units such as (meth) acrylic acid, fumaric acid anhydride, itaconic acid, and crotonic acid And aromatic monomers such as styrene, α-methylstyrene and divinylbenzene, N-substituted unsaturated carboxylic acid amides such as N-methyl (meth) acrylamide, etc., and one kind or two or more kinds. It can also be used in combination. Among them, a monomer having a carboxyl group, a hydroxyl group, a nitrile group or the like is preferably used. The copolymer (A) can be stably produced by copolymerizing these vinyl monomers with methacrylamide, and the protective colloid ability is also improved. Protective colloidal polymerization and seed polymerization can be easily performed.

Emulsion polymer (C) in the present invention
The glass transition temperature of the copolymer (B) constituting the core of the particle, that is, the inside of the particle needs to be in the range of -70 ° C to 0 ° C, preferably -60 ° C to -10 ° C.
More preferably, it is -60 ° C to -20 ° C. If the temperature is lower than -70 ° C, heat resistance and blocking resistance may be deteriorated, and the adhesive strength may be increased, which may impair the releasability. If it exceeds 0 ° C, sufficient adhesiveness cannot be obtained. As the at least two kinds of vinyl monomers constituting the copolymer (B), those exemplified as the vinyl monomer constituting the copolymer (A) can be used in the same manner. A long (meth) acrylic acid ester can be preferably used in order to obtain adhesive performance. On the other hand, a copolymer (B) as another component copolymerizable with the above vinyl monomer
When a component that introduces an unsaturated bond into the main chain is copolymerized, the deterioration due to oxidation and the deterioration due to ozone tend to be large, which is not preferable in the present invention. Representative examples of the component that introduces an unsaturated bond into the main chain of the copolymer (B) include butadiene monomer and natural rubber latex.

As the polymerization initiator used for polymerizing the copolymer (A) and the copolymer (B) in preparing the emulsion polymer (C), water-soluble agents such as persulfate and hydrogen peroxide are used. A hydrophilic initiator, an oil-soluble initiator such as benzoyl peroxide, azobisisobutyronitrile, or a redox initiator is used. The amount of the polymerization initiator is not particularly limited and may be in accordance with a known technique, but when the copolymer (A) containing methacrylamide is prepared, it is 0.1 to 20 parts by weight with respect to 100 parts by weight of the vinyl monomer. It is used in the range of parts by weight, preferably 0.1 to 10 parts by weight. on the other hand,
When the copolymer (B) is produced, it is used in the range of 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the vinyl monomer,
It is preferably 0.1 to 2.0 parts by weight.

Further, when the copolymer (B) is obtained by emulsion polymerization in advance, an emulsifier can be used as necessary to impart stability. For example, higher alcohol sulfates, alkylbenzene sulfonates, aliphatic sulfonates, anionic surfactants such as alkyl diphenyl ether sulfonates, alkyl ester type of polyethylene glycol, alkyl phenyl ethers. Type and alkyl ether type nonionic surfactants may be used alone or in combination of two or more. The amount of these emulsifiers used is not particularly limited, but it is preferable to use the necessary minimum amount.

By using the emulsion polymer (C) obtained above as the main component of the coating layer provided on one side or both sides of the substrate sheet, the adhesive performance under high pressure and the peeling performance under normal conditions can be obtained. It has excellent heat resistance and blocking resistance, and there is no change in characteristics over time,
It is possible to obtain an information carrier sheet having excellent printability. The coating liquid for coating the base sheet contains the emulsion polymer (C) as a main component, but it is no problem to add commonly known fillers, chemicals, etc. within a range that does not impair this performance. It does not become. For example, as a filler, an inorganic filler such as clay, talc, calcium carbonate, titanium dioxide, silica, and aluminum hydroxide, an organic filler such as glass beads and a plastic pigment, an auxiliary binder such as starch, PVA, casein, etc. as a drug, and another defoaming agent, Examples thereof include thickeners and stabilizers. However, the fillers and chemicals that can be added are not limited to those exemplified above, and may be any as long as they do not impair the performance of the emulsion polymer (C).

As a coating method, in principle, a different method may be adopted as long as the above-mentioned coating liquid can be coated on the base sheet. That is, an air knife coater, a rod coater, a hydrobar coater, a blade coater, a transfer roll coater, a river roll coater.
Data, gravure coater, die coater, curtain coater
A known coating machine such as a coater or a spray coater can be used to coat one or both sides of the substrate sheet.

The thus-obtained information carrier sheet of the present invention may be printed with ruled lines or the like on one side or both sides as necessary. The printing method is not limited, but the sheet of the present invention is particularly effective in offset printing using an ultraviolet curable ink. Confidential postcards are included in business forms due to the classification of printing, and offset printing using UV curable ink is usually used for printing business forms. This printing method is a method in which the ink contains a resin that is cured by ultraviolet rays, and after printing, the printed surface is irradiated with intense ultraviolet rays to forcibly cure the ink. In the case of the conventional confidential postcard, it is difficult to maintain a constant adhesive force because the adhesive component is deteriorated by ozone generated by ultraviolet irradiation, but in the present invention, the copolymer (adhesive component) ( If the main chain of B) does not substantially contain a degradable unsaturated bond, there is almost no deterioration due to ultraviolet irradiation.

On the printed information carrier sheet for confidential postcards, the address and individual information are further printed by a non-impact printer (NIP) or the like, if necessary. In NIP, heat is applied to an object to be printed in order to fix the toner.
This step is the most severe in the history of the information carrier sheet, and usually reaches a high temperature of 150 to 180 ° C. When the adhesive component is softened by heat, problems such as soiling the roll in the NIP occur, and therefore the coated surface of the information carrier sheet needs to be devised so as to withstand this heat. In the case of the conventional information carrier sheet for confidential postcards, it was possible to prevent the adhesive from adhering to the roll by making the coated surface uneven as described above, but this method does not improve the printing finish, Further, the filler for making the surface uneven is attached to the blanket of the offset printing machine and causes printing failure. In the present invention, since the copolymer (A) having heat resistance is present outside the emulsion polymer (C) particles and the copolymer (B) having adhesiveness is present inside the particles, the printed surface is smooth. It is possible to satisfy the required heat resistance condition while maintaining the above.

The printed and printed information carrier sheet is
The information surface is adhered using a sealer and folded in two or three. The sealer is formed by arranging two metal rolls in parallel with a slight gap therebetween, and the gap is set to be narrower than the thickness of the information carrier sheet folded in two or three. In this state, by passing a sheet for information carrier folded in two or three in a gap between rolls, a high pressure is applied to the sheet, and a portion where the adhesive components of the emulsion polymer (C) particles in the coating layer overlap each other. It is glued in and a confidential postcard is manufactured.

[0026]

EXAMPLES The present invention will be specifically described below with reference to production examples and examples. In the following examples, all parts and% represent parts by weight and% by weight, unless otherwise specified. Production Example of Copolymer (A-1) 20 water in a separable flask equipped with a stirrer and a reflux condenser.
After charging 0.0 part and 5.0 parts of potassium persulfate and replacing with nitrogen gas, the temperature was raised to 70 ° C. Then, a mixture of a vinyl monomer having the following composition and water was continuously added with stirring over 2 hours, and then the mixture was maintained for 3 hours to complete the polymerization. Then, after cooling to 40 ° C. or lower, the pH was adjusted to 8.0 with aqueous ammonia to obtain an aqueous solution of the copolymer (A-1) having a solid content of about 20% and a glass transition temperature of 100 ° C. Mixed solution of vinyl monomer and water 15 parts of methacrylamide 10 parts of methacrylic acid 10 parts of 2-hydroxyethyl methacrylic acid 57 parts of methyl methacrylate 57 parts of butyl acrylate 8 parts of water 200 parts.

Production Example of Copolymer (A-2) Glass was prepared in the same manner as above except that the mixed solution of the vinyl monomer and water in the above Production Example of Copolymer (A-1) was changed to the following composition. An aqueous solution of the copolymer (A-2) having a transition point temperature of 100 ° C. was obtained. Mixture of vinyl monomer and water methacrylamide 20 parts methacrylic acid 10 parts 2-hydroxyethyl methacrylate 10 parts methyl methacrylate 50 parts butyl acrylate 10 parts water 200 parts.

Production Example of Copolymer (A-3) Glass was prepared in the same manner as above except that the mixed solution of the vinyl monomer and water in the above Production Example of Copolymer (A-1) was changed to the following composition. An aqueous solution of the copolymer (A-3) having a transition temperature of 100 ° C. was obtained. Mixture of vinyl monomer and water 40 parts methacrylamide 10 parts methacrylic acid 35 parts methyl methacrylate 35 parts 2-ethylhexyl acrylate 15 parts water 200 parts.

Production Example of Copolymer (A-4) A glass was prepared in the same manner as above except that the mixed solution of the vinyl monomer and water in the above production example of the copolymer (A-1) was changed to the following composition. An aqueous solution of the copolymer (A-4) having a transition temperature of 150 ° C. was obtained. Mixture of vinyl monomer and water 65 parts methacrylamide 5 parts acrylic acid 5 parts acrylonitrile 10 parts 2-hydroxyethyl methacrylate 10 parts 2-methoxyethyl acrylate 10 parts water 200 parts.

Production Example of Copolymer (A-5) Glass was prepared in the same manner as above except that the mixed solution of the vinyl monomer and water in the above Production Example of Copolymer (A-1) was changed to the following composition. An aqueous solution of the copolymer (A-5) having a transition temperature of 200 ° C. was obtained. Mixture of vinyl monomer and water methacrylamide 80 parts methacrylic acid 5 parts styrene 9 parts 2-hydroxylethyl acrylate 6 parts.

Production Example of Copolymer (A-6) A glass was prepared in the same manner as above except that the mixed solution of the vinyl monomer and water in the above production example of the copolymer (A-1) was changed to the following composition. An aqueous solution of the copolymer (A-6) having a transition temperature of 220 ° C. was obtained. Mixture of vinyl monomer and water 90 parts methacrylamide 2 parts methacrylic acid 5 parts acrylonitrile 5 parts 2-ethylhexyl acrylate 3 parts.

Emulsion Polymers (C-1) to (C-1)
4) Production example: 100 parts of the aqueous solution of the copolymer (A-1) to (A-6) obtained above was placed in a separable flask equipped with a protective colloid polymerization stirrer and a reflux condenser.
Parts, 100 parts of water, and 1.0 part of potassium persulfate were charged, and after substituting with nitrogen gas, the temperature was raised to 70 ° C. Then, the vinyl monomer mixed liquids, which are the components of the copolymers (B-1) to (B-8) having the following compositions, are mixed with the copolymer (A) in various combinations and are mixed in various solids. Polymerization was carried out by continuously dropping the mixture so that the weight ratio was 3 hours. After holding at that temperature for 3 hours, it is cooled to a solid content concentration of about 40
% Of emulsion polymers (C-1) to (C-14) were obtained.

Vinyl monomer mixture liquid composition of copolymer (B-1) 2-ethylhexyl acrylate 35 parts Butyl acrylate 35 parts Ethyl acrylate 20 parts Acrylonitrile 10 parts.

Vinyl monomer mixture liquid composition of copolymer (B-2) 2-ethylhexyl acrylate 35 parts Butyl acrylate 12 parts Acrylonitrile 53 parts.

Vinyl monomer mixture liquid composition of copolymer (B-3) 2-ethylhexyl acrylate 50 parts Butyl acrylate 36 parts Acrylonitrile 14 parts.

Vinyl monomer mixture liquid composition of copolymer (B-4) 2-ethylhexyl acrylate 50 parts Butyl acrylate 46 parts Acrylonitrile 4 parts.

Vinyl monomer mixture liquid composition of copolymer (B-5) 2-Ethylhexyl acrylate 40 parts Butyl acrylate 38 parts Acrylonitrile 22 parts.

Composition of liquid mixture of vinyl monomer of copolymer (B-6) 2-ethylhexyl acrylate 98 parts Divinylbenzene 2 parts.

Vinyl monomer mixture liquid composition of copolymer (B-7) 2-ethylhexyl acrylate 30 parts Methyl methacrylate 23 parts Ethyl acrylate 47 parts.

Vinyl monomer mixture liquid composition of copolymer (B-8) 2-ethylhexyl acrylate 20 parts Butyl acrylate 36 parts Methyl methacrylate 44 parts

Production of emulsion polymer (C-15)
Example: Water 60 in a separable flask equipped with a seed polymerization stirrer and reflux condenser.
0 parts, 1.0 part of sodium dodecylbenzenesulfonate and 5.0 parts of potassium persulfate were charged, and after substituting with nitrogen gas, the temperature was raised to 70 ° C. Next, 1000 parts of a vinyl monomer mixed solution for preparing the copolymer (B-1) [acrylic acid 2-
350 parts of ethylhexyl, 350 parts of butyl acrylate,
200 parts ethyl acrylate, 100 acrylonitrile
Parts], 3.0 parts of sodium dodecylbenzene sulfonate, and 400 parts of water are continuously added dropwise over about 3 hours, and then the resulting mixture is held for 4 hours to obtain a glass transition temperature of emulsion polymerization. -45 ℃, solid content concentration about 50%
The copolymer (B-1) of was obtained. Then, in a similar separable flask, 500 parts of the above copolymer (B-1) and 1 part of water were added.
00 parts and 0.5 parts of ammonium persulfate were charged, the atmosphere was replaced with nitrogen gas, and the temperature was raised to 70 ° C. Then, a mixed liquid of vinyl monomer and water for preparing the copolymer (A-4) [32.5 parts of methacrylamide, 2.5 parts of acrylic acid, 5.0 parts of acrylonitrile, 2-hydroxyethylmethacrylate 5 0.0 parts, 2-methoxyethyl acrylate 5.0
Parts, water 100 parts] was adjusted to a pH of about 8 with aqueous ammonia and then continuously added dropwise over 2 hours for polymerization. The temperature was maintained for 3 hours to obtain an emulsion polymer (C-15) having a solid content concentration of about 40%.

Production of emulsion polymer (C-16)
Example: Seed Polymerization The copolymer (B-1) used in the above production example of the emulsion polymer (C-15) was prepared by adding SBR (styrene-butadiene latex) having a solid content concentration of 50% and a glass transition temperature of about -43 ° C. An emulsion polymer (C-16) was obtained in the same manner as described above, except that the trade name was "Polylac 565-1", manufactured by Mitsui Toatsu Chemicals, Inc.

Production of emulsion polymer (C-17)
Example: Seed Polymerization Emulsion Polymer (C-15) Copolymer (B-1) used in the above Production Example was graft-polymerized with 100 parts of natural rubber by graft polymerization of 10 parts of methyl methacrylate. An emulsion polymer (C-17) was obtained in the same manner as above except that the natural rubber latex (solid content concentration: about 50%) at a temperature of -64 ° C was replaced.

Production of emulsion polymer (C-18)
Example: Copolymer (A-4) obtained in the production example of copolymer (B-1) and copolymer (A-4) obtained in the above production example of polymer blend emulsion polymer (C-15) And (at the solid content weight ratio (A
-4) :( B-1) = 20: 100 were mixed to obtain an emulsion polymer (C-18).

Production of emulsion polymer (C-19)
Example: Water in a separable flask equipped with a random polymerization stirrer and a reflux condenser.
0 parts, 0.8 parts of sodium dodecylbenzene sulfonate and 4.0 parts of potassium persulfate were charged, and after substituting with nitrogen gas, the temperature was raised to 70 ° C. Next, the vinyl monomer constituting the copolymer (A-4) and the vinyl monomer constituting the copolymer (B-1) were uniformly mixed at a solid content weight ratio of 20: 100 below. The vinyl monomer emulsion having the composition was continuously added dropwise over 3 hours to polymerize. After holding at that temperature for 3 hours, it was cooled to obtain an emulsion polymer (C-19) having a solid content concentration of about 40%.

Vinyl monomer emulsion composition Vinyl monomer composition of copolymer (A-4) Methacrylamide 86.7 parts Acrylic acid 6.7 parts Acrylonitrile 13.3 parts 2-Hydroxyethyl methacrylate 13. 3 parts 2-methoxyethyl acrylate 13.3 parts Vinyl monomer composition of copolymer (B-1) 2-ethylhexyl acrylate 233.4 parts Butyl acrylate 233.4 parts Ethyl acrylate 133.3 parts Acrylonitrile 66.6 parts Water 320.0 parts Sodium dodecylbenzene sulfonate 2.4 parts.

The emulsion polymer (C-
Table 1 collectively shows the copolymer (A) and the copolymer (B) used in the production of 1) to (C-19), their weight ratio, the polymerization method and the like.

[0048]

Examples 1 to 11 Emulsion polymer (C-2) [Example 1], (C-
3) [Example 2], (C-4) [Example 3], (C-
5) [Example 4], (C-8) [Example 5], (C-
9) [Example 6], (C-10) [Example 7], (C-
11) [Example 8], (C-12) [Example 9], (C
-13) [Example 10], (C-15) [Example 11]
Was coated on one side of a high-quality paper of 100 g / m ² with an air knife coater to 5 g / m ² (in terms of solid content, the same applies hereinafter), and then dried to produce the information carrier sheet of the present invention. .

Comparative Examples 1 to 8 Emulsion Polymer (C-1) [Comparative Example 1], (C-
6) [Comparative Example 2], (C-7) [Comparative Example 3], (C-1)
4) [Comparative Example 4], (C-16) [Comparative Example 5], (C-
17) [Comparative Example 6], (C-18) [Comparative Example 7], (C
-19) [Comparative Example 8] was coated on one side of high-quality paper of 100 g / m ² using an air knife coater so that the coating amount was 5 g / m ² , and then dried to obtain a comparative sheet. Manufactured.

Comparative Example 9 Acrylic modified rubber latex (degree of acrylate 10%) 5
0 parts by weight and 50 parts by weight of natural rubber latex, 100 parts by weight of silica gel having an average particle size of 4 μm and tapioca starch 3
0 parts by weight was added blended, coating weight of 5 g / m ² on a high-quality paper 100 g / m ² using an air knife coater so
And then dried to produce a comparative prior art sheet.

With respect to the information carrier sheet of the present invention obtained in the above Examples and the comparative sheet obtained in the Comparative Examples, the adhesive strength, blocking resistance, oxidative deterioration degree, and
The results of evaluating the degree of UV (ultraviolet) deterioration and printability are summarized in Table 2. The evaluation method was carried out by the following method, and the evaluation results were shown by the 5-point method. A score of 3 or more indicates excellent performance, and a score of 5 is the best. A score of 2 or less indicates that there is a practical problem.

1) Adhesive strength: After humidity control at 20 ° C./65% RH, the test sample was put under a dry sealer pressure of 50 kg.
/ Cm ² and after pressure bonding, the peel strength by T-type peeling was measured. Tensilon manufactured by Toyo Baldwin Co., Ltd. was used to measure the peel strength, the size of the test sample was 25 mm (width) × 100 mm (length), and the tensile speed was 300 mm / min. In addition, the evaluation point is that the adhesive force is difficult to peel off when the adhesive strength is 200 g or more / 25 mm width,
If the width is less than 50 g / 25 mm width, it may peel off during transportation, so the upper and lower limits are set as the standard. 200 g or more / 25 mm width → 1 point less than 50 g / 25 mm width → 2 points 50 to less than 100 g / 25 mm width → 3 points 150 to less than 200 g / 25 mm width → 4 points 100 to less than 150 g / 25 mm width → 5 points.

[0054]

2) Blocking resistance: 20 ° C./65% R
After adjusting the humidity at H, align the coated surfaces of the test sample,
After applying a pressure of 500 g / cm ² and leaving it at 60 ° C. for 4 hours, the peel strength by T-type peeling was measured. The measuring machine and the measuring conditions of the peel strength are the same as those at the time of measuring the adhesive force except that the size of the test sample is changed to 10 mm (width) × 80 mm (length). 10 g or more / 10 mm width → 1 point 6 to less than 10 g / 10 mm width → 2 points 3 to less than 5 g / 10 mm width → 3 points 1 to less than 2 g / 10 mm width → 4 points 0 g / 10 mm width → 5 points.

3) Oxidation deterioration degree: test sample at 20 ° C.
In the atmosphere of / 65% RH, the coated surface is left in contact with air for 30 days, and the dry sealer pressure is 50 kg / c.
After adjusting to m ² and pressure-bonding, the peel strength by T-type peeling was measured, and the reduction rate of the peel strength due to oxidative deterioration was obtained. The measuring device and the measuring conditions for the peel strength are the same as those for measuring the adhesive force. -50% or more → 1 point -30% to less than -50% → 2 points -20% to less than -30% → 3 points -10% to less than -20% → 4 points Less than -10% → 5 points.

4) UV Degradation: UV was irradiated using a vacuum printing machine for printing equipped with a metal halide lamp manufactured by Eye Graphics Co., and a sample whose humidity was adjusted at 20 ° C./65% RH was dried. -Pressure of 50kg / c
After adjusting to m ² and pressure-bonding, the peel strength by T-type peeling was measured, and the reduction rate of the peel strength by UV deterioration was obtained. The measuring device and the measuring conditions for the peel strength are the same as those for measuring the adhesive force. -50% or more → 1 point -30% to less than -50% → 2 points -20% to less than -30% → 3 points -10% to less than -20% → 4 points Less than -10% → 5 points.

5) Printability: Smoothness, surface strength, and ink acceptability by RI tester were evaluated as substitute evaluation items. Smoothness: Measured by a Beck tester according to JIS P 8119. Surface strength: It was measured by a method using a wax specified in JIS P 8129. The ink acceptability was evaluated by a RI tester. The above items and were comprehensively evaluated with reference to the related art.

[0058]

The evaluation results shown in Table 2 show the following. 1) Comparison of an example using an emulsion polymer (C) with a copolymer (A) in which the solid content weight ratio of methacrylamide was changed, that is, Example 1 (copolymer (A-2) : Methacrylamide 20 parts), Example 2
(Copolymer (A-3): 40 parts of methacrylamide),
Example 3 (Copolymer (A-4): Methacrylamide 6
5 parts), Example 4 (Copolymer (A-5): 80 parts of methacrylamide) and Comparative Example 1 (Copolymer (A-1): 15 parts of methacrylamide), Comparative Example 2 (Copolymer ( A-
6): From the evaluation results of the adhesive strength and blocking resistance of methacrylamide 90 parts), it is possible to achieve both the adhesive strength and the blocking resistance when the solid content weight ratio of methacrylamide is in the range of 20 to 80% by weight. It can be seen that when the solid content weight ratio of methacrylamide is less than 20% by weight, the adhesive strength is strong and the blocking resistance is lowered, and when it exceeds 80% by weight, the adhesive strength is reduced although the blocking resistance is excellent.

2) A comparison between the examples in which the solid content weight ratio of the copolymer (A) / copolymer (B) was changed, and the comparative examples, that is, Example 5 (5/100) and Example 6 (10). / 100),
Example 7 (20/100), Example 8 (30/10)
0), Example 9 (40/100), Example 10 (50 /
100) and Comparative Example 3 (3/100), Comparative Example 4 (60
/ 100), the solid content weight ratio of the shell (copolymer A) and the core (copolymer B) is in the range of A: B = 5: 100 to 50: 100 from the evaluation results of the adhesive strength and the blocking resistance. The adhesive strength and the blocking resistance can be made compatible with each other, but when the ratio of the shell (copolymer A) is less than 5, the adhesive strength is strong and the blocking resistance is lowered, and when it exceeds 50, the blocking resistance is excellent. It can be seen that the adhesive strength of the film is reduced.

3) From the evaluation results of the adhesive strength and blocking resistance of Examples 1 to 10 (protective colloid polymerization) and Example 11 (seed polymerization), at least the adhesive strength and the blocking resistance should be at least satisfied. It is necessary to use an emulsion polymer (C) in which the copolymer (A) is on the surface layer of the particles and the copolymer (B) is distributed inside, and the polymerization method of the emulsion polymer (C) is different. It turns out that it doesn't matter.

4) In Example 3 (the main chain of the copolymer (B) contains substantially no unsaturated bond) and Comparative Examples 5 and 6 (in the main chain of the copolymer (B)) From the evaluation results of the degree of oxidative deterioration and the degree of UV deterioration of the unsaturated bond (including unsaturated bond), it is found that the degree of oxidative deterioration and the degree of UV deterioration increase when an unsaturated bond is present in the main chain of the copolymer (B).

5) Example 7 (copolymer (A) / copolymer (B) = 20/100 in core-shell structure), Comparative Example 7
Adhesion of (copolymer (A) / copolymer (B) = 20/100 and polymer blend) and Comparative Example 8 (copolymer (A) / copolymer (B) = 20/100 and random polymerization) From the evaluation results of the force and the blocking resistance, it is understood that it is difficult to achieve both the adhesive strength and the blocking resistance even if the copolymers (A) and (B) are blended or randomly polymerized.

6) Comparative Example 9 is an example of the prior art in which fine particles were used in combination to apply a coating solution mainly for the purpose of preventing blocking, and this and Examples 1 to 11 (co-weighing) The polymer (B) does not substantially contain an unsaturated bond in the main chain and does not contain fine particles that hinder the printability).
Compared to Comparative Example 9, the examples all have substantially no unsaturated bond in the main chain of the copolymer (B) distributed inside the emulsion polymer, and thus the degree of oxidative deterioration and the degree of UV deterioration are small.
Further, it is understood that the printability is excellent because the coating liquid does not contain fine particles.

[0065]

Since the sheet for information carrier of the present invention is constructed as described above, it has the following remarkable effects. 1) Since the contradictory characteristics of the adhesive performance and the heat resistance performance can be made compatible, the adhesive performance and the blocking resistance are excellent in balance. 2) Since an acrylic copolymer that does not substantially contain an unsaturated bond in its main chain is used as a copolymer that exhibits adhesiveness, the effects of oxidative deterioration and UV deterioration on adhesive strength are hardly seen. 3) It becomes possible to introduce adhesive performance and heat resistance,
Since it is no longer necessary to add particles having a large particle diameter to the coating liquid composition, the printability is superior to the conventional one. 4) The information carrier sheet of the present invention utilizes various performances described above, such as various maturity guides for financial institutions, account transfer notifications, checking account check slips, transaction statements, and insurance premium withdrawal notifications for insurance operations. Various payment notices, tax exemption certificates, credit usage statements, dunning letters, account transfer notifications, government tax payment notifications, pension payment notifications, various account transfer completed notifications, securities business transaction reports, Balance statement, educational institution report,
It can be suitably used for applications such as pass / fail judgment notices, tuition payment notices, medical examination result reports, various direct mails, bills and other pay statements, lottery tickets, and the like. In addition to the two-fold and three-fold forms described so far,
It is also possible to adopt an arbitrary form such as a form in which a larger number of folds are inserted, or a form in which a plurality of single sheets are stacked and adhered without folding in a certain sheet.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09J 7/02 JLE // B42D 15/02 501 B (72) Inventor Shinjiro Sakurai Sakae-ku, Yokohama-shi, Kanagawa 1190 Kasamacho Mitsui Toatsu Chemicals, Inc. Research Institute (72) Inventor Yoshio Kikuta 1190 Kasamacho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemicals Research Institute

Claims (4)

[Claims] 1. A sheet for information carrier comprising a base sheet, on one or both sides of which a coating layer having adhesive properties under high pressure and peeling properties under normal conditions is formed, wherein the main component of the coating layer is meta. From copolymer (A) consisting of at least one vinyl monomer copolymerizable with acrylamide and methacrylamide and at least two vinyl monomers having a glass transition temperature of -70 ° C to 0 ° C And the copolymer (B) is contained in one particle, the copolymer (A) is distributed substantially in the surface layer of the particle, and the copolymer (B) is distributed substantially inside the particle. Use of emulsion polymer (C) particles, copolymer (A) in the emulsion polymer (C)
And the solid content weight ratio of the copolymer (B) is A: B = 5: 10.
0 to 50: 100, and the copolymer (A)
The solid content weight ratio of methacrylamide in
80% by weight of the information carrier sheet. 2. The emulsion polymer (C) particles are
2. The information carrier sheet according to claim 1, which has a structure in which at least a part of the surface of the particles of the copolymer (B) is covered with the copolymer (A). 3. The information carrier sheet according to claim 1, wherein the copolymer (A) has a glass transition temperature of 100 ° C. to 200 ° C. 4. The information carrier sheet according to claim 1, wherein the copolymer (B) does not substantially contain an unsaturated bond in its main chain.