JPS62135389A - Thermal sticking preventive agent for thermal transfer material - Google Patents

Abstract

PURPOSE:To provide a thermal transfer material having favorable printing performance, by using a composition comprising a specified polysiloxane graft polymer and heat-resistant fine particles as a thermal sticking preventive agent. CONSTITUTION:A composition comprising heat-resistant particles having an average particle diameter of primary particles of not more than 0.5mum and a polysiloxane graft polymer obtained by polymerizing a polymerizable silane compound, an unsaturated organic acid and other monomer copolymerizable therewith in a specified ratio in the presence of a hydroxyl-terminated polysiloxane is used as a thermal sticking preventive agent when producing a thermal transfer material by providing a thermally transferable ink layer 2 on one side of a base film 1 and providing a thermal sticking preventive layer 3 on the other side. By this, a thermal sticking preventive layer can be obtained which facilitates treatments of the base film, has favorable adhesion to the base film, and has excellent heat resistance, slipping properties and thermal sticking preventing capability.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a novel thermal stick prevention agent for thermal transfer materials. More specifically, in a heat-sensitive transfer material consisting of a base film and a heat-transferable ink layer provided on one surface of the film, a heat stick prevention layer is provided on the other surface of the base film, so that the ink is applied from a heating head. A thermal stick prevention agent for thermal transfer materials that prevents part of the base film from melting and adhering to the heating head due to heat pulses, and also provides lubricity to allow smooth heating head movement and paper feeding. Regarding.

(Prior Art) In recent years, facsimile machines and printers have frequently used a thermosensitive recording method in which a thermosensitive coloring layer in which two components are dispersed that produce color when heated is provided on a base material. However, this method has drawbacks such as poor storage stability, easy falsification after recording, and poor solvent resistance. A transfer type thermal recording system is known as a method for improving these drawbacks.

In this method, a thermally transferable ink layer such as a printed layer is generally provided on a receiving sheet (for example, plain paper) by passing a thermal transfer material through the thermal pulse of a heating head.

As the base film of the heat-sensitive transfer material, a plastic film is suitable from the viewpoint of film thickness, strength, and moisture resistance, and a polyester film or the like is used.

(Problems to be Solved by the Invention) Recently, there has been a desire to improve printing performance and printing speed in transfer-type thermal recording methods, such as reducing the thickness of the base film or increasing the amount of heat applied to the heating head. However, with these methods, the heat load applied to the base film becomes large, causing the base film to melt and
This creates a problem that hinders the running of the heating head. Such a phenomenon is generally called a thermal stick phenomenon.

Various attempts have been proposed to improve this thermal stick phenomenon. For example, JP-A No. 55-7467 proposes a method of applying a heat-resistant resin such as silicone resin, epoxy resin, or nitrocellulose to one side of the base film. A heat curing treatment of several hours is required, and nitrocellulose does not require a heat curing treatment, but has the problem that the heat generated by the heating head causes decomposition of the nitrocellulose and generates oxidizing gas.

In addition, JP-A-56-155794 discloses a composition consisting of a heat-resistant polymer and an inorganic powder such as fine silica or talc, but it has the drawback that the heat curing process requires a long time, and The surface was likely to become rough, and there remained a problem in the running performance of the heating head. Furthermore, JP-A-60-15193 discloses a composition consisting of colloidal particles of silica and alumina and an organic binder such as polyvinyl alcohol, which is intended to smooth the surface, but the heat resistance of the composition itself The slipperiness of the membrane surface still remains inadequate.

The present invention solves the above-mentioned conventional problems, and its purpose is to provide an excellent thermal stick prevention agent for thermal transfer materials.

(Means and effects for solving the problem) As a result of intensive research into heat stick preventive agents, the present inventors found that heat-resistant products with specific polysiloxane graft polymers and primary particles with an average particle diameter of 0.5μ or less The present invention has been completed based on the discovery that a composition consisting of the same particles can solve the conventional problems.

That is, in the present invention, a polymerizable silane compound (
B) 0.05-10% by weight, unsaturated organic acid (C) 0.5
~10ffiffi% and other polymerizable monomers copolymerizable with these (,0)60~98.45! Polysiloxane graft polymer obtained by polymerizing 1% by weight (however, the total of components (A), (B), (C) and (D) is 100% by weight) (I> and the average of primary particles) The present invention relates to a thermal stick prevention agent for thermal transfer materials comprising heat-resistant particles (II) having a particle size of 0.5 μm or less.

To illustrate an application example of the thermal stick prevention agent for thermal transfer materials of the present invention, it is as shown in FIG. A thermal transfer material having a thermal stick prevention layer 3 containing the thermal stick prevention agent of the present invention as a main component on its surface can be mentioned.

The thermal stick prevention layer containing the thermal stick prevention agent for thermal transfer materials of the present invention as a main component has good heat resistance and slipperiness.
It has a high heat stick prevention ability and good adhesion to the base film, and can be easily applied to the base film using an ordinary coating machine or printing machine.

Polysiloxane graft polymer used in the present invention (
The terminal human Oxyl group-containing polysiloxane (A) used as a component constituting I) has the general formula R1 (wherein R and R are each independently a monovalent halogen-substituted hydrocarbon group, (n is an integer of 1 or more), and various types are currently readily available and can be used depending on the purpose. The molecular weight of the polysiloxane (A) used is preferably one in which n is in the range of 10 to 2,000. If n is less than 10, the resulting thermal stick preventive agent will not exhibit sufficient surface properties such as desired lubricity, and if n exceeds 2000, it will have a high viscosity.
This is not preferred because handling and polymerization operations become difficult. In addition to the polysiloxanes represented by the general formula above, polysiloxanes having partially branched side chains can also be used as the polysiloxane (A) without any problem.

The amount of the terminal hydroxyl group-containing polysiloxane (A) to be used can be determined as appropriate within the range of 1 to 20% by weight depending on the degree of surface modification. If the amount used is 1% by weight, the surface properties are not sufficient, and if it exceeds 20% by weight, the adhesion to the base film decreases, which is not desirable.

The polymerizable silane compound (B) used in the present invention is a compound having in its molecule at least one polymerizable unsaturated group and at least one group capable of condensation reaction with the polysiloxane. Methoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinyltris(β-methoxyethoxy)silane, allyltriethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane , γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyljethoxysilane, γ-(meth)acryloxypropyltris(β-methoxyethoxy)silane, 2-styrylethyltrimethoxysilane , (meth)acryloxyethyldimethyl(3-trimethoxysilylpropyl)ammonium chloride, vinyltriacetoxysilane, vinyltrichlorosilane, etc., and one type or a mixture of two or more types selected from these groups. can be used.

The amount of the polymerizable silane compound (B) to be used can be determined as appropriate within the range of 0.05 to 10% by weight.

If the amount used is less than 0.05ffi1%, the bond between polysiloxane (A) and the polymer consisting of components (B), (C) and (D) will be insufficient, and an effective amount of graft reaction will not occur, resulting in the polysiloxane Graft polymer (I) tends to undergo layer separation. In addition, in a range exceeding 10% by weight,
Gelation during polymerization tends to occur, resulting in poor stability of the polysiloxane graft polymer (I).

The unsaturated 11!1 (C) used in the present invention is an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, itacon Fi, etc., if it induces a bond between the polysiloxane (A) and the polymer. Examples include unsaturated sulfonic acids such as Yagonylsulfonic acid, sulfoethyl methacrylate, and 2-acrylamido-2-methylpropanesulfonic acid, and one type or a mixture of two or more of these can be used.

The amount of unsaturated 1111'1l (C) used is 0.5 to 1
It can be adjusted as appropriate within the range of 0% by weight. 0.5
If the amount of ffi used is less than 11%, it will be difficult to cause an effective amount of graft reaction, and if it exceeds 10% by weight, it will be difficult to maintain the balance between the polymerization reaction and the grafting reaction, and the resulting heat loss will be reduced. This will impair the surface modification effect such as lubricity and adhesion of the anti-stick agent.

Examples of the polymerizable monomer (b) used in the present invention include acrylic esters such as butyl acrylate and 2-ethylhexyl acrylate; methacrylic esters such as methyl methacrylate and butyl methacrylate; acetic acid Vinyl esters such as vinyl and vinyl propionate; Aromatic vinyls such as styrene and vinyltoluene; Unsaturated nitriles such as acrylonitrile and methacrylate; Unsaturated amides such as acrylamide and N-methylolacrylamide: ethylene, propylene, α-olefins such as isobutylene; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and t-butyl vinyl ether; vinyl chloride, vinylidene chloride, vinyl fluoride,
Halogen-containing α, β-unsaturated monomers such as vinylidene fluoride; trifluoroethyl (meth)acrylate, 2.2.
3.3-tetrafluoropropyl acrylate, 18.
1H.

2. Fluorine-containing (meth)acrylic acid esters such as 2-1-hebutadecafluorodecyl acrylate and IH, IH, 5H-octafluoropentyl acrylate: 2.
Examples include aromatic fluorine-containing (meth)acrylic esters such as 3,5.6-titrafluorophenyl acrylic ester and 2.3,4.5.6-pentafluorophenyl methacrylic ester. One type or a mixture of two or more types can be used.

The amount of the polymerizable monomer (b) to be used can be determined as appropriate within the range of 60 to 98.45% by weight. If the amount used is less than 60% by weight or more than 98.45% by weight, the amount of the polysiloxane (A), polymerizable silane compound (B) or unsaturated organic 1 (C) used is in excess of the above range. Otherwise, the amount becomes too small, which is undesirable because the above-mentioned drawbacks occur.

Polysiloxane graft polymer used in the present invention (
I) is a terminal hydroxyl group-containing polysiloxane (A)
In the presence of polymerizable silane compound (8), unsaturated organic! [
! It can be produced by polymerizing (C) and other polymerizable monomers (D) copolymerizable with these using conventionally known polymerization methods. For example, solvents that can be used when employing the solution polymerization method include toluene, hexane, methyl ethyl ketone, ethyl cellosolve, ethyl acetate, isopropyl alcohol, etc. One type or a mixture of two or more of these can be used. You can. Also,
Examples of the polymerization initiator include common radical polymerization initiators such as azobisisobutyronitrile and benzoyl peroxide.

Reaction humidity ranges from room temperature to 200°C, preferably 40 to 120°C.
℃ range.

The heat-resistant particles (I) with an average primary particle diameter of 0.5μ or less used in the present invention are not particularly limited as long as they are made of a material that does not decompose or melt at a temperature of 200°C or less, such as Examples include inorganic or organic fine particles such as titanium oxide, iron oxide, zirconium oxide, antimony oxide, silicon oxide, carbon black, amino resins such as melamine resin and benzoguanamine resin, and fluorine resin, and all of them are average particles of -order particles. Fine particles with a particle size of 0.5 μm or less are selected and used. Specific examples of heat-resistant particles (I) that can be effectively used include Triotx R-100 (manufactured by Fuji Titanium Co., Ltd.), transparent iron oxide 5E-DBS (manufactured by Domura Oil @ J), and titanium. Black 12S (manufactured by Mitsubishi Metals ■), etc. are used, and organic fine particles include amino resin spherical fine particles Epostor S (Nippon Shokubai Chemical Co., Ltd. H!!#).

Polysiloxane graft polymer (I) and heat-resistant particles (
The mixing ratio with II) may be appropriately determined depending on the lubricity and heat resistance of the thermal stick preventive agent to be obtained, but is generally in the range of (I):(II)-100:1 to 100:100. is suitable.

The thickness of the heat stick prevention layer is preferably 0.1 to 5 microns. The thermal stick prevention layer can be formed by coating or printing using the thermal stick prevention agent of the present invention by a conventionally known method. A crosslinking agent and/or a curing catalyst may be appropriately selected and used. Particularly suitable are polyaziridine or polyisocyanate compounds which can be cured even at low temperatures. Further, when forming the heat stick prevention layer, it is also possible to improve workability by appropriately using a surfactant or a solvent.

As the base film, conventionally used ones can be used.
Examples include polyester film, polycarbonate film, cellulose acetate film, polypropylene film, and cellophane.

The heat transferable ink layer is a conventionally used heat-melting ink layer or a heat-sublimable dye-containing layer, and is formed by coating or printing using a conventionally known method.

(Effects of the Invention) The thermal stick prevention agent for thermal transfer materials of the present invention is easy to process and exhibits good adhesion to the base film, and has excellent heat resistance, slipperiness, and thermal stick prevention ability. The present invention provides a thermal transfer material that forms a thermal stick prevention layer and has good printing performance.

(Examples) The present invention will be specifically described below with reference to Examples, but the present invention is not limited in any way by these. In addition, all parts in the examples indicate parts by weight.

Reference Example 1 In a four-neck flask equipped with a thermometer, a reflux condenser, a dropping funnel, a nitrogen inlet tube, and a stirrer, 30% of dihydroxydimethylpolysiloxane having the formula (where n is 1500 on average) as a polysiloxane containing terminal hydroxyl groups was prepared.
10 parts of a wt% toluene solution and 100 parts of toluene were charged, and the temperature was raised to 80°C under a nitrogen atmosphere. Add to this 64.4 parts of methyl methacrylate, 20 parts of butyl acrylate, and acrylic! ! 15 parts, hydroxyethyl acrylate 5.6
part, γ-methacryloxypropyltrimethoxysilane 5
1 part and 2 parts of azobisisobutyronitrile were added thereto, and the mixture was heated at 80°C for 30 minutes.
Initial polymerization was performed. Next, the remaining monomer homogeneous solution was added dropwise over a period of 2 hours at the same temperature, and when the polymerization was continued for 20 minutes after the addition was completed, 100 parts of isopropyl alcohol was added to dilute the solution. Continue to maintain the temperature at 80°C for 3 hours at 40°C.
After stirring for several minutes to continue the polymerization reaction, the solution was cooled and the polysiloxane graft polymer solution (hereinafter referred to as polymer solution (1)) was obtained.

) was obtained. The viscosity of the obtained polymer solution (1) was 50c
ps (25° C., B-type viscometer, 60 RL), and the solid content was 33.3% by weight.

Reference Example 2 Add Reference Example 1 to a four-bottle flask similar to that used in Reference Example 1.
33.3 parts of a 30% by weight toluene solution of the same terminal hydroxyl group-containing polysiloxane as used in the above and 100 parts of toluene were charged, and the temperature was raised to 80° C. under a nitrogen atmosphere. To this, 50 parts of methyl methacrylate, 20 parts of butyl acrylate, 20 parts of acrylonitrile, 5 parts of acrylic acid, γ
- Using a homogeneous monomer solution consisting of 5 parts of methacryloxypropyltrimethoxysilane and 2 parts of azobisisobutyronitrile, the same initial polymerization operation and dropping operation of the homogeneous monomer solution as in Reference Example 1 were performed. . When the polymerization was continued for 30 minutes after the dropwise addition of the monomer homogeneous solution, 100 parts of ethyl alcohol was added to dilute the solution. The reaction was further continued at 80° C. for 3 hours and 30 minutes, and then cooled to obtain a polysiloxane graft polymer solution (hereinafter referred to as polymer solution (2)). The viscosity of the obtained polymer solution (2) was 7
The solid content was 0 cps (25° C., B-type viscometer, 60 rpm) and 33.0% by weight.

Example 1 100 parts of the polymer solution (1) obtained in Reference Example 1, transparent iron oxide 5E-DBS (manufactured by Okamura Oil Co., Ltd., average particle size 0.0
3-0.08μ) 6.6 parts, cationic surfactant Alucard T-50 (manufactured by Lion Akzo ■) 10.6 parts,
3.1 parts of polyaziridine compound Chemitite PZ-33 (manufactured by Nippon Shokubai Chemical Industry Co., Ltd.), 140 parts of toluene, and 70 parts of isopropyl alcohol were mixed to form a thermal stick prevention agent for thermal transfer materials of the present invention (hereinafter referred to as thermal stick prevention agent). (referred to as agent (1)) was prepared. This thermal stick prevention agent (1) was coated on one side of a polyethylene terephthalate base film with a thickness of 6 μm using a bar coater and then dried by heating to form a thermal stick prevention layer with a thickness of 1.5 μm. Next, the other side of the base film was coated with a thickness of 2 μm.
A heat-transferable ink layer was provided to obtain a heat-sensitive transfer material (1).

2 100 parts of the polymer solution (2) obtained in Reference Example 2, Titanium Black 12S (manufactured by Mitsubishi Metals ■, average particle size 0.05μ)
6.6 parts, Sumidur IL (50% butyl acetate solution of polyisocyanate compound, manufactured by Sumitomo Chemical ■) 18.
7 parts of toluene, 140 parts of toluene, and 70 parts of isopropyl alcohol were mixed to prepare a thermal stick prevention agent for thermal transfer materials of the present invention (hereinafter referred to as thermal stick prevention agent (2)). This heat stick prevention agent (2) was applied to one side of a polyethylene terephthalate base film with a thickness of 6 μm using a bar coater, and then heated and dried to a thickness of 1.5 μm.
A thermal stick prevention layer of μ was formed. Next, a heat-transferable ink layer having a thickness of 2 μm was provided on the other side of the base film to obtain a heat-sensitive transfer material (2).

Example 3 100 parts of the polymer solution (1) obtained in Reference Example 1, 6.6 parts of Eposter S (manufactured by Nippon Shokubai Chemical Co., Ltd., spherical fine particles made of amino resin, average particle size 0.3μ), 5.0 parts of dibutyltin dilaurate. 3 parts, 140 parts of toluene, and 70 parts of isopropyl alcohol were mixed to prepare a thermal stick prevention agent for thermal transfer materials of the present invention (hereinafter referred to as thermal stick prevention agent (3)).

This thermal stick prevention agent (3) was coated on one side of a polyethylene terephthalate base film with a thickness of 6 μm using a bar coater and then dried by heating to form a thermal stick prevention layer with a thickness of 1.5 μm. Next, a heat-transferable ink layer having a thickness of 2 μm was provided on the other side of the base film to obtain a heat-sensitive transfer material (3).

Comparative Example 1 Comparative thermal transfer was performed in the same manner as in Example 1 except that the transparent iron oxide 5E-DBS (manufactured by Domura Oil Co., Ltd., average particle size 0.03 to 0.08 μ) in Example 1 was not used. Heat stick prevention agent for materials (hereinafter referred to as comparative heat stick prevention agent)
1). ) was prepared.

Using this comparative thermal stick prevention agent (1), a thermal stick prevention layer was formed in the same manner as in Example 1, and then a thermal transferable ink layer was provided to obtain a comparative thermal transfer material (1).

Comparative Example 2 100 parts of a 30% by weight toluene solution of the dihydroxydimethylpolysiloxane used in Reference Example 1, 4.8 parts of dibutyltin dilaurate, 100 parts of toluene and 40 parts of isopropyl alcohol were mixed to prepare a heat-sensitive transfer material for comparison. Anti-stick agent (hereinafter referred to as comparative thermal anti-stick agent (2)
). ) was prepared. Using this comparative thermal stick prevention agent (2), a thermal stick prevention layer was formed in the same manner as in Example 1, and then a thermal transferable ink layer was provided to obtain a comparative thermal transfer material (2).

Comparative Example 3 A comparative thermal transfer material (3) was obtained in the same manner as in Example 1 except that the heat stick prevention layer was not formed.

Examples 4 to 6 and Comparative Examples 4 to 6 Thermal transfer materials (1) to (3) and comparative thermal transfer materials (1) to (3) obtained in Examples 1 to 3 and Comparative Examples 1 to 3, respectively. A thermal transfer test was conducted on recording paper using a thermal head printing test device (manufactured by Matsushita Electronic Components).

Note that the test conditions were that the applied voltage was 20 V and the printing speed was 2 milliseconds.

The presence or absence of a thermal stick phenomenon during the thermal transfer test was evaluated by observing the running state of the thermal head. The contamination state of the thermal head after the thermal transfer test was also investigated. These results are shown in Table 1.

Chapter 1 Table

[Brief explanation of drawings]

FIG. 1 is a diagram (a cross-sectional view of a thermal transfer material) showing an application example of the thermal stick prevention agent for thermal transfer materials of Honsharo. 1. Base film 2, thermal transfer ink layer 3, thermal stick prevention layer

Claims (1)

[Claims] 1. Terminal hydroxyl group-containing polysiloxane (A) 1-
In the presence of 20% by weight, 0.0% of polymerizable silane compound (B)
5 to 10% by weight, unsaturated organic acid (C) 0.5 to 10% by weight, and other polymerizable monomers (D) copolymerizable with these 6
0 to 98.45% by weight (however, (A), (B), (C)
The total of components (D) and (D) is 100% by weight. ) obtained by polymerizing polysiloxane graft polymer (I
) and heat-resistant particles (II) whose primary particles have an average particle diameter of 0.5 μm or less.