JPH08269340A - Sheet for image forming - Google Patents

Abstract

PURPOSE: To obtain a sheet for an image forming using a heat transcription method, exhibiting an excellent releasing properties over a wide temperature range and suitable for heat sensitive sheet, etc., by applying a polymer having an organo polysiloxane component in the main chain, etc., of the basic skeleton of the polymer as a heat releasing agent. CONSTITUTION: This sheet for an image forming is obtained by applying a polymer such as a polyester, a polyurethane and a polyamide having an organo polysiloxane such as dimethylpolysiloxane in the main chain or in the side chain of the basic skeleton of the polymer as a heat releasing agent. Furthermore, it is preferable that the basic skeleton of the polymer of the heat releasing agent is constituted by the polymer of an ethyleneic unsaturated monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer type image forming sheet releasing agent, and more particularly to an image forming sheet having excellent releasing property even in a wide temperature range, especially under heating.

[0002]

2. Description of the Related Art Conventionally, as a release agent used for producing molded articles such as plastics, silicone resins, various waxes, stearates, tetrafluoroethylene resins, etc. Widely used. These release agents are used by being added to the polymer to be molded or applied to the molding die. In addition, when attention is paid to the use form or properties of the release agent, for example, it is used as an oil-type release agent, a paste-type release agent, an aerosol-type release agent, a solution-type release agent, or an emulsion-type release agent. Have been. Furthermore, what is generally known as release paper can be obtained by applying and curing a silicone resin on the surface of a base paper.

By the way, the above-mentioned conventional mold release agent is sufficiently effective as a mold release agent used in a usual plastic molding process using a mold, for example, but it is a specific product completed. When it is used for the purpose of imparting releasability to, it is not always sufficiently satisfactory. That is, for example, in a technique of forming an image by a thermal transfer system, a thermal transfer sheet having a dye layer and an image receiving sheet (heat transfer target sheet) are superposed and heat-printed by a thermal head to form a desired image on the image receiving sheet. Releasability is one of the important characteristics required for the above-mentioned sheets used in this case. In other words, since the thermal transfer sheet and the image receiving sheet are superimposed and heated as described above, it is important that both sheets have excellent releasability (or ease of peeling) after printing in order to smoothly perform image formation. Further, since each sheet is usually used before and after printing, it is an important characteristic that the releasability should be provided in preventing blocking between the sheets. In addition to the above-mentioned sheet-like products, there are products such as various coated products for which good releasability (non-adhesiveness) on the surface is particularly required.

However, products using the above-mentioned conventional release agents have the following problems.

(A) In the thermal transfer sheet and the image receiving sheet as described above, each sheet is instantaneously exposed to a high temperature during heating printing by a thermal head, but in a sheet using a conventional release agent, The releasability at the time of application of such high energy is not always satisfactory, and disadvantages such as heat fusion occurring at a printed portion or inevitable mass transfer between the opposing sheet surfaces. There is.

(B) Conventionally, when a release property is imparted to a synthetic resin sheet product or a coated product as described above, a method of adding a release agent such as silicone to a raw material polymer is usually employed. However, conventional release agents generally do not have good compatibility with the raw material polymer.Therefore, after the preparation of the raw material composition or the formation of the coating film, the release agent component undergoes phase separation to flow, migrate, or There is a problem in that various adverse effects are caused, such as deterioration on the surface layer over time and deterioration of the releasability over time.

(C) In the case of a conventional release agent, when a resin layer or a coating film having releasability is formed on a certain base material, it is inevitably formed with the base material for the release agent to be added. The adhesiveness between the layers must be reduced, so that the excellent releasability on the surface of the forming layer and the mutually inconsistent properties of the adhesiveness between the base material and the forming layer are combined. Conventional release agents are not satisfactory for application.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and exhibits excellent releasability over a wide temperature range, stability over time, It is an object of the present invention to provide an image forming sheet having an excellent effect in improving the storage stability.

In order to achieve the above object, the image-forming sheet according to the present invention comprises a polymer having an organopolysiloxane component in the main chain or side chain of the basic skeleton of the polymer as a thermal release agent. It is characterized by that.

Hereinafter, the thermal release agent according to the present invention will be described in more detail.

In the following description,% representing a quantitative ratio is based on weight unless otherwise specified.

The thermal release agent according to the present invention basically comprises a polymer having an organopolysiloxane represented by the following general formula in the main chain or side chain of the polymer.

[0013]

Embedded image In the above formula, R and R ′ are an alkyl group such as a methyl group, an ethyl group, a propyl group or an aryl group such as a phenyl group, and are —OH, —NH ₂ , —NH—, —COOH, epoxy It may contain a functional group such as a group. And R,
R 'may be the same or different. Further, n is 8 to 1.
It is preferably an integer in the range of 20.

In the heat releasing agent according to the present invention,
Depending on the purpose, binders, dyes, pigments, surfactants,
Other additives such as an antioxidant may be used in combination.

Hereinafter, the above-mentioned heat releasing agents will be described in two types, that is, a main chain type and a side chain type, focusing on the bonding position of the organopolysiloxane to the basic skeleton of the polymer. As the main chain type main chain type, for example, a polymer whose basic skeleton is made of polyester, polyurethane, polyamide or the like is preferably used. Specifically, it is a polymer as shown below.

[0016]

Embedded image In the above formula, R ₁ , R ₂ , R ₃ , and R ₄ each generally represent a methylene group having 4 to 30 groups or a phenyl group, but may be the following bisphenol.

[0017]

Embedded image Further, in the above formula of the main chain type polymer, each of the bonds (I) and (II) is an ester bond when the basic skeleton is polyester, a urethane bond when it is polyurethane, and an amide bond when it is polyamide. It is a combination.

The main chain type heat-releasing polymer having the above-mentioned structure is a silicone-modified polymer containing an organopolysiloxane component in its main chain. The amount of silicone modification in the polymer is preferably 3 to 3% based on the total weight of the polymer.
It is 50%, more preferably 5 to 30%. If the silicone modification amount is less than 3%, the heat release effect is insufficient, while if it exceeds 50%, gelation occurs during polymerization, lack of uniformity of polymerization, and it becomes difficult to obtain a transparent polymer, which is not preferable. .

The molecular weight of these silicone-modified polymers is 5,000 to 50,000 and the degree of polymerization is 10 to 10
About 0 is preferable.

Next, a method for synthesizing the main chain type polymer will be described. Silicone-modified polyester Usually, it can be synthesized by polycondensation of a diol component having a primary alcoholic hydroxyl group at both terminals of an organopolysiloxane as described below and a dicarboxylic acid component.

Dialkyl polysiloxane modified diol:

[0022]

[Chemical 4] In the above formula, n is an integer within the range of 8 to 120.

Dicarboxylic acid component: HOOC-R-COOH In the above formula, R is a methylene group (the number of methylene groups is 4 to 30).
Is) or a phenyl group.

The silicone-modified polyester can be synthesized by polymerization of the above-mentioned dialkylpolysiloxane component and dicarboxylic acid component, and may appropriately contain the following diol components in addition to the above two components. As such a diol component, a component containing a phenyl group, such as bisphenol A, bisphenol B, bisphenol AF, and bisphenol S, or a component having no phenyl group may be used.

In synthesizing the above-mentioned polymer, each of the above-mentioned components may be a single type or a mixture of plural types. Silicone-modified polyurethane Usually, it can be synthesized by a polyaddition reaction of a diol component having a primary alcoholic hydroxyl group at both ends of the above-mentioned organopolysiloxane with the following diisocyanate.

Diisocyanate: Tolylene diisocyanate (TDI) Diphenylmethane diisocyanate (MDI) Hexamethylene diisocyanate (HMDI) Diisocyanates such as isophorone diisocyanate (IPDI).

The silicone-modified polyurethane can be synthesized by polymerization of the dimethylpolysiloxane component and the diisocyanate component. In addition to the above two components, the same diol component as described in the description of the silicone-modified polyester is used. Can be used. Silicone Modified Polyamide Usually, it can be synthesized by polycondensation of a diamine component having a primary amino group at both terminals with an organopolysiloxane as described below and a dicarboxylic acid component.

Dialkylpolysiloxane modified diamine:

[0029]

Embedded image In the above formula, n is an integer within the range of 8 to 120.

Dicarboxylic acid component: HOOC-R-COOH In the above formula, R is a methylene group (the number of methylene groups is 4 to 30).
Is) or a phenyl group.

Further, the silicone-modified polyamide in this case can also be synthesized by polycondensation of a dicarboxylic acid component having a carboxyl group at both ends of a dimethylpolysiloxane and a diamine component as shown below.

Dialkylpolysiloxane-modified dicarboxylic acid:

[0033]

[Chemical 6] In the above formula, n is an integer within the range of 8 to 120.

Diamine component: H ₂ N—R—NH _{2 In the} above formula, R is a methylene group (the number of methylene groups is 2 to 12).
Or a modified diamine containing a phenyl group, O, S, or the like.

The silicone-modified polyamide can be synthesized by the above-described two-component system polymerization. In the synthesis, each component does not have to be a single component, and for example, a plurality of types of components are appropriately mixed and used. can do. Side chain type polymer The side chain type polymer has an organopolysiloxane component in the side chain of the basic skeleton of the polymer. A silicone graft copolymer obtained by copolymerizing a macromonomer (macromer) with an ethylenically unsaturated monomer such as an acrylic or vinyl monomer by attaching the side chain type polymer to the synthesis method.

As the above silicone macromonomer,
For example, the following may be used.

[0037]

[Chemical 7] The classification is as follows.

(1) Silicone having a (meth) acrylic group In the above formula, n is an integer in the range of 5-120.

(2) A silicone-modified polymer obtained by reacting a silicone compound with a previously obtained polymer to pendant the silicone.

For example, a polymer having a reactive group such as a hydroxyl group, a carboxyl group, an amino group, or an epoxy group on the skeleton of the main chain, a carboxyl group at a terminal,
By reacting a silicone compound having a hydroxyl group, an amino group, an epoxy group, or an isocyanate group, the silicone can be pendant on the side chain of the polymer.
Specifically, a combination of the following two reactive groups can be considered.

Polymer Silicone Hydroxyl group Carboxyl group Hydroxyl group Isocyanate group Carboxyl group Hydroxyl group Carboxyl group Amino group Carboxyl group Epoxy group Amino group Carboxyl group Amino group Epoxy group Epoxy group Carboxyl group Epoxy group Amino group The above methods (1) and (2) The side chain type heat-releasing polymer obtained by the above is a silicone-modified polymer characterized by containing a dimethylpolysiloxane component in the side chain. In this case, the amount of silicone modification is preferably 5 to 70%, more preferably 1 to 70% based on the total amount of the polymer.
It is 0 to 50%. If the silicone modification amount is less than 5%, the heat releasing effect is insufficient, while if it exceeds 70%, on the contrary, thickening or gelation occurs during polymerization or reaction, and high transparency cannot be obtained. It is not preferable. The molecular weight of these silicone-modified polymers is 5,000 to 50.
The range of 000 is preferable. Actions / Effects As described above, the image-forming sheet according to the present invention is formed by applying a thermal release agent made of a polymer having an organopolysiloxane component in the main chain or side chain of the polymer.
It has the following excellent properties. (A) Thermal releasability It has excellent releasability in a wide temperature range, especially under high temperature heating, and therefore exhibits excellent effects as various sheets for image formation by the thermal transfer method. In particular, it is possible to solve the problem of heat fusion caused by heating printing. (B) Lubricity Since an excellent effect of reducing friction is exhibited as an effect of silicone, an image forming sheet having good slipperiness can be obtained. (C) Water repellency (oil repellency) Since it has the effect of increasing the contact angle of the surface and remarkably improving the water repellency and oil repellency, it is possible to obtain an image forming sheet excellent in stain resistance. (D) Compatibility Since the silicone component in the applied heat release agent has a structure bonded to the polymer that is the basic skeleton, even if it is added as a compounding component to another polymer composition, As described above, phase separation and other problems that occur when a silicone resin is added alone are unlikely to occur. (E) Adhesion Since the basic structure other than the silicone component of the polymer constituting the heat release agent contributes to the improvement of the adhesion (adhesion) to the substrate, the image forming sheet also has excellent characteristics in this respect. Can be obtained. (G) Silicone stain resistance When added to a specific polymer composition, in a conventional release agent (for example, silicone), the release agent component may have various adverse effects on other products. For example, a thermal transfer sheet and an image receiving sheet are usually stacked or stored in a roll state.
There is a problem that a blocking phenomenon easily occurs between the sheets due to the release agent component. However, in the thermal release agent of the present invention, since the silicone component is bonded to the skeleton polymer, the above-mentioned problem of contamination due to the silicone component itself is solved. (H) High molecular weight Since the thermal release agent itself has a large molecular weight, it is advantageous in terms of strength and also has excellent weather resistance, and is formed as a coating film on another substrate. It also has an excellent effect on the film forming property in some cases. Therefore, the present invention
In this respect and the above point (d), it has an excellent effect in storage stability and stability over time.

[0042]

EXAMPLES Synthesis examples and test examples of the thermal release agent of the present invention will be described below. Synthesis Example 1 675 g of dimethyl terephthalate, 225 g of dimethyl isophthalate, (mixing ratio 75:25), 810 g of ethylene glycol, silicone modified diol, X-22-1
1480 g of 60B (manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.81 g of litharge as a catalyst are placed in a three-necked flask and heated and stirred at 140 to 240 ° C. for 3.5 hours while introducing N ₂ . After all the methanol has been distilled off, the pressure is reduced to 10 mmHg, and the excess glycol is distilled off. Then, 1mmHg
Further, the pressure was further reduced, and the mixture was reacted at 270 ° C. for 9 hours to make it have a high molecular weight, to obtain a silicone-modified polyester. Synthesis example 2 54 g of 1,4-butanediol, a silicone-modified diol, Silaprene FM4411 (manufactured by Chisun Corporation) 100
g, methyl ethyl ketone (MEK) 154g as a solvent
In a three-necked flask, and dibutyltin dilaurate 0.3
Add g and stir well. Next, a solution in which 133 g of diphenylmethane diisocyanate was dissolved in 133 g of MEK was appropriately mixed, and the mixture was heated and stirred for 5 hours while adjusting the mixed reaction solution so as not to be 80 ° C. or higher, to obtain a silicone-modified polyurethane. Synthetic Example 3 Hexamethylenediamine 5.8 g, silicone modified diamine, Silaprene FM3311 (manufactured by Nissin Corporation) 10
g, surfactant Emulgen 106 (manufactured by Kao Corporation) 0.10
g, 110 g of water are well emulsified and dispersed in a flask, then 12 g of triethylamine is added, and the periphery is cooled with ice. Then, 11 g of adipic acid chloride was added to toluene 4
Dissolve in 4 g and cool similarly. The cooled diamine solution is poured into the reaction vessel of the homomixer for interfacial polymerization, and then the acid chloride solution is gently poured to form an interface, and the surroundings are cooled with ice. Then, the mixture was rotated at a high speed with a homomixer to perform interfacial polymerization. The produced polymer was thoroughly washed with water and dried. Synthesis Example 4 375 g of a mixed (1: 1) solution of methyl isobutyl ketone and ethyl acetate was placed in a three-necked flask, and the mixture was refluxed in a warm bath while introducing N ₂ . Next, 25 g of 2-hydroxyethyl acrylate, 125 g of methacrylic acid methyl ester, silicone-modified acryl, Silaplane F
100 g of MO711 (manufactured by Nippon Steel Co., Ltd.) and 2.5 g of α, α′-azobisisobutyronitrile are mixed and dropped into a refluxing solution under stirring to carry out radical solution polymerization. After the dropping was completed, the mixture was further stirred for 2 hours to obtain a polymer. Synthesis Example 5 100 g of ethyl acetate was placed in a three-necked flask, and the mixture was stirred and refluxed in a warm bath while introducing N ₂ . Then, 30 g of acrylic acid and 70 g of methacrylic acid methyl ester were dropped into the reflux solution to carry out radical solution polymerization. next,
Silicone modified one end epoxy, Silaplane FMO
A mixed solution of 200 g of 521 (manufactured by Nitrogen Co., Ltd.) and 200 g of ethyl acetate was added dropwise, and the reaction between a carboxyl group and an epoxy group was performed at 80 ° C. using pyridine as a catalyst.
Stirring was performed for 3 hours to obtain a silicone-modified graft copolymer. Examples and Comparative Examples The polymers obtained in Synthesis Examples 1 to 5 were each PET100
coating on μ to a thickness of 10 g / m ² ,
After drying, various properties of the coating film were examined. The results are shown in Table 1 below.

Evaluation:…: particularly excellent…: good Δ: slightly problematic ×: bad 1) Thermal releasability Judgment was made based on the peeling strength of cellophane tape.

Coated surfaces are combined, 150 ° C. × 1k
After heat-sealing under the condition of g / cm ² × 1 second, it was peeled from the end and the releasability was judged.

2) Slidability Whether or not the friction coefficient is reduced as compared with the polymer not modified with silicone is used as a criterion.

3) Stainability of Magic Ink After drawing a line on the coated surface with Magic Ink ^R, it was immediately wiped off with absorbent cotton, and contamination of the ink before and after was judged.

4) Adhesion Adhesion to PET 100 μm was evaluated by a cross-cut test.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C08L 101/10 LTB C08L 101/10 LTB

Claims (9)

[Claims] 1. A sheet for image formation by a thermal transfer system, wherein a polymer having an organopolysiloxane component in a main chain or a side chain of a basic skeleton of the polymer is applied as a thermal release agent. 2. The image forming sheet according to claim 1, wherein the thermal release agent further contains another additive. 3. The image forming sheet according to claim 1, wherein the basic skeleton of the polymer of the thermal release agent is polyester. 4. The image forming sheet according to claim 1, wherein the basic skeleton of the polymer of the thermal release agent is polyurethane. 5. The image forming sheet according to claim 1, wherein the basic skeleton of the polymer of the thermal release agent is polyamide. 6. The image forming sheet according to claim 1, wherein the basic skeleton of the polymer of the thermal release agent is a polymer of an ethylenically unsaturated monomer. 7. The image forming sheet according to claim 1, wherein the organopolysiloxane is dimethylpolysiloxane. 8. The image forming sheet according to claim 1, wherein the image forming sheet is a thermal transfer sheet. 9. The image forming sheet according to claim 1, wherein the image forming sheet is an image receiving sheet.