JP2002052817A - Translucent recording medium for ink jet recording and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a translucent recording medium for ink jet recording capable of suppressing an adverse influence to be given to an environment to a maximum limit in the case of a waste disposal after using by incorporating excellent transparency, OHP suitability, heat resistance, ink jet recording suitability such as ink absorbability, color development or the like. SOLUTION: The translucent recording medium for ink jet recording made of a translucent base comprises a translucent base made of a matrix of a silicon oxide made by a decomposition polymerization of an organic silicon compound and a saccharide material made of a cellulose, an oligosaccharide or their derivatives so that the silicon oxide and the saccharide material are made of the polymer substance made of at least one bond of a hydrogen bond, siloxane bond, urethane bond, urea bond and amide bond and an ink receiving layer having pores provided in a surface layer of the base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light transmitting recording medium for ink jet recording and a method for manufacturing the same, and more particularly to a light transmitting recording medium suitable for ink jet recording for an overhead projector (OHP) and a method for manufacturing the same.

[0002]

2. Description of the Related Art Ink jet recording is a method of ejecting ink as small droplets from fine nozzles to record characters and figures on the surface of a recording medium as a recording medium. The ink jet recording method uses an electrostrictive element to convert an electric signal into a mechanical signal, and continuously or intermittently ejects the ink stored in the nozzle head portion, and prints characters, symbols, and graphics on the surface of the recording medium. Recording method, and Japanese Patent Application Laid-Open No. 54-59
According to the method described in Japanese Patent Application Publication No. 936-936, the ink subjected to the action of thermal energy causes a rapid volume change, and the ink is continuously or intermittently ejected from the nozzles by the action force due to this state change. A method of recording characters, symbols, and figures on the surface of a recording medium has been put to practical use.

In recent years, ink-jet recording has attracted attention as a recording method capable of achieving low noise, high speed, and colorization, and has been widely used. As a recording medium used in this recording method, a recording medium in which a porous ink receiving layer is provided on a base material, which is conventionally called an ink jet recording paper, or an overhead projector (OHP) is used. ) Has been used. In particular, when it comes to OHP recording media, these constituent materials, mainly the materials constituting the base material, include polyester resins, diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, and polyvinyl chloride. Films such as resin and polyimide resin are used.

On the other hand, the amount of synthetic plastic materials used in various industrial fields tends to increase year by year, and accordingly, the amount of synthetic plastic waste also increases, and the treatment thereof has become a major social problem worldwide. ing. Some of these waste plastics are collected and incinerated, while others are disposed of in landfills. In general, when synthetic plastics are incinerated, they generate a large amount of heat and may cause damage to the incinerator, and many synthetic plastics generate harmful gases when incinerated. Moreover, in the case of landfill disposal, the problem of securing a disposal site and the problem of adverse effects on the natural environment cannot be ignored.

Under these circumstances, with regard to consumables used in an ink jet recording apparatus, the problem of disposal of consumables after use has become important with the spread of the apparatus due to environmental problems and the like. Is coming. In particular, as for the recording medium for OHP, as described above, since the base material is made of synthetic plastic, sufficient consideration must be given to disposal treatment after use. However, in the conventional OHP film for ink-jet, the above-mentioned disposal treatment is not considered, and when a large amount of waste is generated, there is a concern that it may adversely affect the environment. In consideration of this problem, JP-A-6-239014 and JP-A-9-393.
No. 79 proposes a recording medium using a biodegradable plastic sheet as a base material.

[0006] However, although the above-mentioned recording medium is a recording medium that is excellent in ink-jet recording suitability and suppresses adverse effects on the environment, the recording medium for OHP, unlike fibrous paper, has poor ink absorbency. for that reason,
There is a contrivance to heat the OHP recording medium to speed up the drying of the ink. However, since the heat resistance of the OHP recording medium is inferior, the recording medium may be deformed. It is also disclosed that an OHP recording medium is used as a base material and an ink receiving layer is provided on a surface layer. However, if the temperature applied to the substrate in the drying step of the receiving layer is not lower than 120 ° C., heat shrinkage of the substrate becomes a problem.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art.
Its purpose is high transparency, excellent OHP suitability, excellent heat resistance, ink jet recording suitability such as ink absorbency and color development, and the adverse effects of waste upon disposal after use on the environment. It is an object of the present invention to provide a recording medium used for inkjet which has excellent characteristics capable of minimizing the amount of ink.

[0008]

That is, the present invention relates to a light-transmitting recording medium for ink jet recording comprising a light-transmitting substrate, wherein the light-transmitting substrate is formed by decomposing and polymerizing an organosilicon compound. Composed of a product matrix (fine three-dimensional network structure) and a saccharide material composed of cellulose, oligosaccharide or a derivative thereof, and a silicon oxide and a saccharide material formed of hydrogen bond, siloxane bond, urethane bond, urea An ink receiving layer comprising a polymer substance comprising at least one of a bond and an amide bond, and an ink receiving layer having pores on a surface layer of the light-transmitting substrate. It is a transparent recording medium.

Further, the present invention provides a method comprising reacting an organosilicon compound with a saccharide material comprising cellulose, oligosaccharide or a derivative thereof, and decomposing and polymerizing the organosilicon compound to form a silicon oxide matrix and a saccharide material. And a step of obtaining a light-transmitting substrate comprising a polymer material comprising at least one of a hydrogen bond, a siloxane bond, a urethane bond, a urea bond, and an amide bond, wherein the silicon oxide and the saccharide material are A method for producing a light-transmitting recording medium for ink jet recording, comprising a step of forming pores in a surface layer of a light-transmitting substrate and providing a receiving layer.

[0010] The pores are formed by dissolving only a part of the saccharide material portion of the light-transmitting substrate with a solvent or photothermally melting by irradiation with ultraviolet laser light.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, the light-transmitting substrate comprises a silicon oxide matrix and a saccharide material,
A light-transmitting substrate, wherein the silicon oxide and the saccharide material are a polymer substance comprising at least one of a hydrogen bond, a siloxane bond, a urethane bond, a urea bond, and an amide bond; A light-transmitting recording medium for ink-jet recording, characterized in that an ink receiving layer based on pores is provided on a surface layer of a material.

That is, the recording medium of the present invention composed of the above-mentioned materials has not only high transparency and excellent OHP suitability but also good ink jet suitability and excellent heat resistance. Therefore, heating for drying the ink is possible.

Further, by selectively removing only a part of the saccharide material portion in the surface layer of the light-transmitting substrate, it is possible to form pores for further improving ink receptivity. The presence of the pores makes it easier to hold the ejected ink droplets on the substrate, and can accelerate the drying of the ink by increasing the surface area and capillary action.

Further, in the recording medium of the present invention, since the base material occupying all or most of the medium has biodegradability,
When disposed, it is possible to minimize adverse effects on the environment.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. The recording medium of the present invention is a saccharide material (cellulose, oligosaccharide, and derivatives thereof).
And a polymer substance that is a reaction product of a silicon oxide from an organosilicon compound. That is, the polymer substance constituting the recording medium of the present invention is composed of a saccharide material which is a biodegradable substance and a silicon oxide which is a component of soil, and has not only heat resistance but also high transparency. have.

Particularly, as a recording medium for OHP, 10
%, It is preferable to use a substrate made of a material having a haze (turbidity) of not more than 0.1%. Note that the haze degree is one of the indexes of translucency, and is represented by the following equation (1).

[0017]

(Equation 1)

Preferred examples of such a synthetic polymer of a silicon oxide and a saccharide material are shown below. Sugars include cellulose, oligosaccharides, and derivatives thereof. Oligosaccharides mean from disaccharides to about decasaccharides, and are classified into homooligosaccharides composed of a single saccharide and heterooligosaccharides composed of two or more types of monosaccharides, and are particularly preferred. The cellulosic oligosaccharides such as cellobiose, cellotriose and cellotetraose, maltose,
And starch-based oligosaccharides such as maltotriose and maltotetraose, and sucrose heteroheterosaccharides.
Examples of the derivatives include acetylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and the like, acetylated products of each oligosaccharide (such as acetylcellobiose), esterified products (such as cellobiose adipate), and etherified products (such as hydroxyethylmaltose).
And so on.

As the organosilicon compound, the following formula (2)
The compound represented by these is mentioned.

[0020]

(Equation 2)

(Wherein R ′ represents a lower alkyl group having about 1 to 4 carbon atoms which may have a substituent or an aryl group which may have a substituent, and R ″ represents a carbon atom having a substituent. Represents about 1 to 4 lower alkyl groups, and R 'and R "may be the same or different depending on n. N represents an integer of 0 to 2)

Specific examples of the organosilicon compound include trimethoxysilane, triethoxysilane, tripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, and propyltrimethoxysilane. , Methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ -Mercaptopropyltriethoxysilane,
γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, aminobutyltrimethoxysilane, aminobutyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane There is silane and the like.

A method of combining cellulose, oligosaccharide or a derivative thereof with a silicon oxide is to hydrolyze and polymerize the saccharide material and the organosilicon compound in an organic solvent with an acid such as hydrochloric acid. This is done by producing a silicon oxide matrix. Examples of the organic solvent that can dissolve both the saccharide material and the organosilicon compound include tetrahydrofuran, methanol, ethanol, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone.

The bonds between the above-mentioned cellulose, oligosaccharides and derivatives thereof and the silicon oxide obtained by the decomposition polymerization of the above-mentioned organosilicon compound are hydrogen bonds (-OH ... O <),
Siloxane bond (-O-Si-), urethane bond (-N
H-CO-O-), urea bond (-NH-CO-NH)
-) And an amide bond (-NH.CO-).

In the recording medium of the present invention, the weight ratio of the silicon oxide is from 10 to 50% by weight, preferably from 10 to 30% by weight, in order to make the light-transmitting substrate light-transmissive. desirable.

The weight-average molecular weight of the polymer composed of the silicon oxide-saccharide material thus obtained is preferably about several thousand to several hundred thousand, more preferably 10,000 to 100,000. Use around 10,000.

The thickness of the light-transmitting substrate of the recording medium of the present invention is arbitrary according to the specifications of the ink jet recording apparatus to be used, and is not particularly limited. A light-transmitting substrate having a thickness of about 25 to 300 μm is preferably used.

Next, in order to further improve the printing quality in the present invention, a method of providing pores serving as a physical ink receiving layer in the surface layer of the light-transmitting substrate will be described. When the bond between the silicon oxide and the saccharide material is a hydrogen bond, and the saccharide material is soluble in an organic solvent, a part of the saccharide material in the light-transmitting surface layer is dissolved by the organic solvent. Holes can be created. However, the contact time with the organic solvent must be appropriately controlled in order to prevent collapse of the entire substrate and loss of transparency.

Examples of the organic solvent include tetrahydrofuran, methanol, ethanol, propanol, pyridine, dimethylformamide, dimethylacetamide, dimethylsulfoxide, hexamethylphosphoric triamide, sulfolane and N-methylpyrrolidone. Is desirably selected according to the solubility of the compound.

When the bond between the silicon oxide and the saccharide material is a hydrolyzable covalent bond, the covalent bond is hydrolyzed with an acid or a base, and then the pores are formed by the same treatment with an organic solvent as described above. Can be done. Also,
In this case, if the saccharide material is a water-soluble cellulose derivative, oligosaccharide, or oligosaccharide derivative, elution with an organic solvent is not necessarily required.

Further, pores can be generated by photothermally ablating a part of the saccharide material on the surface layer by irradiation with ultraviolet laser light. This is an application of known laser ablation, and the surface treatment of the substrate can be performed in an extremely high-speed and clean environment. It is desirable that the light used in this treatment has a wavelength that is hardly absorbed by the silicon oxide and easily absorbed by the saccharide material. Further, a bond between a silicon oxide and a saccharide material, or a saccharide material itself containing a carbonyl group is preferable because it helps these conditions. That is, the carbonyl group

[0032]

[Outside 1] Part of the saccharide material is decomposed to form pores by local heat radiation generated by absorption of light having a transition wavelength and internal conversion of excitation energy, or by hydrogen abstraction reaction by an excited carbonyl group.

The laser suitable for the above conditions is K
rF excimer laser (248 nm), XeCl excimer laser (308 nm), nitrogen laser (337 n)
m), Nd: YAG laser (fourth harmonic, 266n
m), a dye laser (around 300 nm) and the like.

[0034]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples.

Example 1 and Reference Example 1 10 g of acetylcellulose having a degree of acetylation of 40% was added to T
It was dissolved in 40 g of HF (tetrahydrofuran), and 8.44 g of tetramethoxysilane was added. 2.5 g of 1N hydrochloric acid was added, and the mixture was stirred at room temperature for 2 hours to obtain a reaction product. As a result of measuring the molecular weight, the weight average molecular weight was about 30,000. This reaction product was cast into a film having a thickness of 80 μm. In the infrared absorption spectrum of the film,
Si-O-Si stretching (near 1130 cm ^-1 ) was observed, confirming the formation of a silicon oxide matrix.
(Reference Example 1)

This film-shaped substrate (hydrogen bond type) was immersed in dimethylformamide for 5 minutes, and then washed and dried with water and ethanol. (Example 1) The contact angle of a water droplet was measured before and after this treatment. As a result, the contact angle was reduced from 54 degrees before the treatment to 28 degrees after the treatment. The transparency of the film after the treatment was 93% on average in the visible light region, and the haze was 0.5%, which was good. Thermal properties are 300
There was no change up to about ° C, and the heat resistance was good.

Next, the above-mentioned film-shaped recording medium was evaluated for OHP suitability and biodegradability by ink jet recording by the following methods. (OHP aptitude by inkjet recording) Using an inkjet printer (BJC-600J, manufactured by Canon Inc.), a full-color image was recorded on the recording medium obtained above,
For comparison, recording was performed on a commercially available OHP film for color inkjet (manufactured by Canon Inc .: CF-102), and each image was projected with a reflective OHP and observed visually.

As a result, when an image equivalent to or higher than that of the commercial product was obtained, the result was evaluated as ○, when an image more than that was obtained, as ◎, and when the image was inferior to the commercial product, ×. And

(Biodegradability) The recording medium in the form of a biodegradable film was buried in compost soil, and after 6 months, it was observed whether or not the biodegradation had progressed.

A sample having a decomposable property was rated as ○, and a sample having no degradable property was rated as x.

The results are shown in Table 1. It was found that the recorded image as OHP was equivalent to a commercially available product and also had biodegradability.

Example 2 and Reference Example 2 10 g of cellobiose and 9 g of 3-isocyanatopropyltriethoxysilane were reacted in dimethylformamide to give 8.5 g of a cellobiose derivative having a urethane bond.
Was synthesized. 3. 2.0 g thereof and tetraethoxysilane
0 g was dissolved in 50 g of ethanol solvent to form a homogeneous solution, and 1.0 g of 1N hydrochloric acid was added to the solution, and the solution was allowed to react at room temperature in the atmosphere for 4 days while stirring. The weight average molecular weight was about 10,000 to 15,000. This reaction product was cast into a film having a thickness of 80 μm. In the infrared absorption spectrum of the film, Si—O—Si expansion and contraction (around 1130 cm ⁻¹ ) was observed, and formation of a silicon oxide matrix was confirmed.
(Reference Example 2)

This film-shaped substrate was immersed in a 0.01N aqueous solution of sodium hydroxide for 10 minutes, and then washed and dried with water and ethanol. (Example 2) The contact angle of a water droplet was measured before and after this treatment. As a result, the contact angle was reduced from 50 degrees before the treatment to 34 degrees after the treatment. The transparency of the film after the treatment was 90% in the visible light range.
% And the haze were 1.9%. Regarding heat resistance,
There was no change up to 250 ° C.

Next, the suitability for OHP and the biodegradability were evaluated in the same manner as in Example 1. The results are also shown in Table 1. The OHP suitability was better than before the treatment, and the biodegradability was also good.

Example 3 and Reference Example 3 10 g of acetylcellulose having a degree of acetylation of 40% was dissolved in 120 ml of tetrahydrofuran (THF).
9 g of isocyanatopropyltriethoxysilane in THF
Was added to the solution dissolved. Further, a solution prepared by dissolving a few drops of di-n-butyltin dilaurate in THF was added as a catalyst, and the mixture was stirred and reacted at room temperature for 12 hours. Next, the urethane-bonded cellulose-silanized product is dissolved in THF, 0.005N hydrochloric acid is added and stirred, and further reacted with a solution of tetramethoxysilane dissolved in 0.01N hydrochloric acid to give a weight average molecular weight of about 25,000. A polymer material was obtained.
The urethane-bound cellulose-silicon oxide thus obtained was formed into a film having a thickness of 90 μm by a roll coating method. In the infrared absorption spectrum of the film, S
i-O-Si stretching (around 1130 cm ^-1 ) was observed,
The formation of a silicon oxide matrix was confirmed. (Reference Example 3)

A pulse light (308 n) of a XeCl excimer laser (Lambda Physics LPX-100) was applied to the film-like substrate (urethane-bonded type) produced in Reference Example 3.
m, 100 mJ / pulse), and then washed with running water and dried. (Example 3) When the contact angle of a water droplet was measured at a place where laser light was not irradiated and at a place where laser light was not irradiated, a decrease in the contact angle was observed from 52 degrees before irradiation to 26 degrees after irradiation. The transparency of the film after the treatment was good with an average transmittance of 92% and a haze of 0.7% in the visible light region. The thermal characteristics did not change up to around 300 ° C., and the heat resistance was good.

Next, the suitability for OHP and the biodegradability were evaluated in the same manner as in Example 1. The results are also shown in Table 1. OHP
Suitability was better than before treatment, and biodegradability was also better.

Comparative Example 1 Using a copolymer film of polyhydrobutyrate and valerate (Biopol, manufactured by Zeneca), the suitability for OHP and the biodegradability by ink-jet recording were evaluated in the same manner as in Example 1. As a result, although having biodegradability, OH
It was found that P suitability was poor.

[0049]

[Table 1]

[0050]

As described above, the light transmitting recording medium for ink jet recording according to the present invention has high transparency,
OHP by inkjet recording because of low haze
Since it has excellent suitability and good heat resistance, there is no deformation of the film due to heat shrinkage and the like, and there is an advantage in shortening the time for the drying step and the like. Furthermore, since it has good biodegradability, it is possible to minimize adverse effects on the environment when disposed.

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Claims (4)

[Claims] 1. A light-transmitting recording medium for ink-jet recording comprising a light-transmitting substrate, wherein the light-transmitting substrate comprises a silicon oxide matrix obtained by decomposing and polymerizing an organosilicon compound, and cellulose, oligosaccharide or A saccharide material comprising a derivative thereof; and the silicon oxide and the saccharide material comprising a polymer substance comprising at least one of a hydrogen bond, a siloxane bond, a urethane bond, a urea bond, and an amide bond. And a light transmitting recording medium for ink jet recording, wherein an ink receiving layer having pores is provided on a surface layer of the light transmitting substrate. 2. A method comprising reacting an organosilicon compound with a saccharide material comprising cellulose, oligosaccharide or a derivative thereof to decompose and polymerize the organosilicon compound, comprising a silicon oxide matrix and a saccharide material; A step in which the oxide and the saccharide material obtain a light-transmitting substrate composed of a polymer substance comprising at least one of a hydrogen bond, a siloxane bond, a urethane bond, a urea bond, and an amide bond; A method for producing a light-transmitting recording medium for inkjet recording, comprising a step of forming a pore in a surface layer of a material and providing a receiving layer. 3. The method for producing a light-transmitting recording medium for ink-jet recording according to claim 2, wherein the pores are formed by dissolving only a part of the saccharide material portion of the light-transmitting substrate with a solvent. 4. The light-transmitting recording medium for ink-jet recording according to claim 2, wherein the pores are formed by photothermally ablating only a part of the saccharide material portion of the light-transmitting substrate by irradiation with ultraviolet laser light. Production method.