U.S. patent application number 16/539335 was filed with the patent office on 2019-12-05 for transfer type ink jet recording method and transfer type ink jet recording apparatus.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Fumihiro Goto, Nobuyuki Kuwabara.
Application Number | 20190366706 16/539335 |
Document ID | / |
Family ID | 63791907 |
Filed Date | 2019-12-05 |
![](/patent/app/20190366706/US20190366706A1-20191205-D00000.png)
![](/patent/app/20190366706/US20190366706A1-20191205-D00001.png)
![](/patent/app/20190366706/US20190366706A1-20191205-D00002.png)
![](/patent/app/20190366706/US20190366706A1-20191205-D00003.png)
![](/patent/app/20190366706/US20190366706A1-20191205-D00004.png)
![](/patent/app/20190366706/US20190366706A1-20191205-D00005.png)
![](/patent/app/20190366706/US20190366706A1-20191205-D00006.png)
United States Patent
Application |
20190366706 |
Kind Code |
A1 |
Kuwabara; Nobuyuki ; et
al. |
December 5, 2019 |
TRANSFER TYPE INK JET RECORDING METHOD AND TRANSFER TYPE INK JET
RECORDING APPARATUS
Abstract
In a transfer type ink jet recording method, the temperature of
an intermediate image in a heating step is not lower than the
minimum coat forming temperature of a first resin and is not lower
than the glass transition temperature of a second resin, and the
temperature of the intermediate image in a transfer step is lower
than the glass transition temperature of the first resin and is not
lower than the glass transition temperature of the second
resin.
Inventors: |
Kuwabara; Nobuyuki;
(Hachioji-shi, JP) ; Goto; Fumihiro;
(Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
63791907 |
Appl. No.: |
16/539335 |
Filed: |
August 13, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15946923 |
Apr 6, 2018 |
10421270 |
|
|
16539335 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B41M 5/03 20130101; B41J
2002/012 20130101; B41M 5/0256 20130101; C09D 11/106 20130101; B41J
11/002 20130101; B41J 2/0057 20130101; C09D 11/30 20130101; C09D
11/322 20130101; B41M 5/506 20130101; B41M 7/009 20130101; C09D
11/54 20130101; B41M 5/0011 20130101; C09D 11/40 20130101; C09D
11/38 20130101; B41J 2/01 20130101 |
International
Class: |
B41J 2/005 20060101
B41J002/005; B41M 5/50 20060101 B41M005/50; B41J 2/01 20060101
B41J002/01; B41J 11/00 20060101 B41J011/00; B41M 5/00 20060101
B41M005/00; B41M 5/025 20060101 B41M005/025; C09D 11/30 20060101
C09D011/30 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 14, 2017 |
JP |
2017-080795 |
Claims
1. A transfer type ink jet recording method comprising: a liquid
applying step of applying a liquid containing a first resin to a
transfer member; an intermediate image forming step of applying, to
the transfer member applied with the liquid, an ink containing a
second resin to thereby form an intermediate image; a heating step
of heating the transfer member on which the intermediate image is
formed; and a transfer step of transferring the intermediate image
subjected to the heating step to a recording medium, wherein: in
the heating step, a surface temperature of the transfer member is
not lower than a minimum coat forming temperature of the first
resin and is not lower than a glass transition temperature of the
second resin; and a surface temperature of the transfer member
immediately after the transfer step is lower than a glass
transition temperature of the first resin and is not lower than the
glass transition temperature of the second resin.
2. A transfer type ink jet recording apparatus comprising: a
transfer member; a liquid applying device configured to apply, to
the transfer member, a liquid containing a first resin; an
intermediate image forming unit configured to apply, to the
transfer member applied with the liquid, an ink containing a second
resin to thereby form an intermediate image; a heating device
configured to heat the transfer member on which the intermediate
image is formed; and a transfer unit configured to transfer the
intermediate image on the transfer member heated by the heating
device to a recording medium, wherein: a surface temperature of the
transfer member heated by the heating device is not lower than a
minimum coat forming temperature of the first resin and is not
lower than a glass transition temperature of the second resin; and
a surface temperature of the transfer member immediately after
transferring the intermediate image to the recording medium is
lower than a glass transition temperature of the first resin and is
not lower than the glass transition temperature of the second
resin.
3. The transfer type ink jet recording apparatus according to claim
2, wherein the liquid has a resin emulsion containing resin
particles formed of the first resin, and the minimum coat forming
temperature is a minimum film forming temperature of the resin
particles.
4. The transfer type ink jet recording apparatus according to claim
2, wherein the glass transition temperature of the first resin is
higher than the glass transition temperature of the second
resin.
5. The transfer type ink jet recording apparatus according to claim
2, wherein the glass transition temperature of the first resin is
80.degree. C. to 100.degree. C.
6. The transfer type ink jet recording apparatus according to claim
2, wherein the first resin is an acrylic resin or a urethane
resin.
7. The transfer type ink jet recording apparatus according to claim
2, wherein the glass transition temperature of the second resin is
40.degree. C. to 60.degree. C.
8. The transfer type ink jet recording apparatus according to claim
2, wherein the second resin is an acrylic resin or a urethane
resin.
9. The transfer type ink jet recording apparatus according to claim
2, wherein the transfer member has a surface roughness Ra of 0.1
.mu.m or less.
10. The transfer type ink jet recording apparatus according to
claim 2, further comprising a controlling unit for selecting
execution or non-execution of application of the liquid.
11. The transfer type ink jet recording apparatus according to
claim 2, further comprising a cooling device for cooling the
transfer member which is heated by the heating device.
12. The transfer type ink jet recording apparatus according to
claim 2, wherein the minimum coat forming temperature of the first
resin is 50.degree. C. to 90.degree. C.
13. The transfer type ink jet recording apparatus according to
claim 2, wherein the surface temperature of the transfer member
heated by the heating device is 80.degree. C. to 200.degree. C.
14. The transfer type ink jet recording apparatus according to
claim 2, further comprising a reaction liquid applying device
configured to apply a reaction liquid containing a component that
increases viscosity of the ink.
15. The transfer type ink jet recording apparatus according to
claim 2, wherein the component that increases viscosity of the ink
is polyvalent metal ion or organic acid.
16. The transfer type ink jet recording apparatus according to
claim 2, wherein the first resin is a glossy layer-forming
material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of
application Ser. No. 15/946,923, filed Apr. 6, 2018, which claims
the benefit of Japanese Patent Application No. 2017-080795, filed
Apr. 14, 2017. All prior applications are hereby incorporated by
reference herein in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a transfer type ink jet
recording method and a transfer type ink jet recording
apparatus.
Description of the Related Art
[0003] Ink jet recording apparatuses are characterized by low
running cost, the apparatus structure capable of achieving
downsizing and applicability to color image recording using a
plurality of color inks and have been widely used as output devices
for computers and the like. As the digitization of photographs
proceeds, ink jet recording apparatuses are also used to output
images onto recording media on the basis of the digital information
on photographs.
[0004] A typical ink jet recording apparatus applies inks directly
onto a recording medium to form an image, and thus the type of a
recording medium may affect the image quality. To address this, ink
jet recording apparatuses are required to have a function capable
of outputting a high quality image at a high speed regardless of
the types of recording media.
[0005] A known ink jet recording apparatus meeting the above
requirement is a transfer type ink jet recording apparatus
including a transfer member. The transfer type ink jet recording
apparatus forms an image by the following procedure: an
intermediate image is first formed on a transfer member; and then
the intermediate image is transferred from the transfer member onto
a recording medium. In this procedure, liquid components can be
removed from an intermediate image on the transfer member before
the transfer of the intermediate image onto a recording medium.
Subsequently, the intermediate image from which the liquid
components have been removed is transferred onto a recording
medium, and thus feathering of the image on the recording medium
can be suppressed even when high speed printing is performed. By
changing conditions for removing liquid components from an
intermediate image on the transfer member, the water content in the
intermediate image can be controlled, and this enables output on a
wide variety of recording media.
[0006] Meanwhile, image transferability is required to be improved
to transfer an intermediate image from a transfer member to a
recording medium. Methods of improving the image transferability
are disclosed in Japanese Patent Application Laid-Open No.
H07-32721 and International Publication No. WO94/01283.
[0007] Japanese Patent Application Laid-Open No. H07-32721
discloses an apparatus using a transfer type ink jet recording
method in which an ink containing a thermoplastic resin is used, a
transfer drum is heated at a temperature not lower than the
softening point or the melting point of the resin and a heated ink
image is transferred. International Publication No. WO94/01283
discloses an apparatus using a transfer type ink jet recording
method in which an ink containing a resin emulsion having a minimum
film forming temperature of 50.degree. C. or more is ejected on a
transfer medium that is heated to have a surface temperature not
lower than the minimum film forming temperature, and then solvent
evaporation and transfer are performed.
[0008] As the digitization of photographs has become common,
photoprinting by ink jet recording utilizing the above
characteristics has been popularized. Silver halide photographs
have high glossiness and express sophisticated feeling, and thus
photoprinting by ink jet recording is also required to yields an
image having high glossiness. To achieve high glossiness of an
image output by the ink jet recording, the following methods can be
performed. In other words, a pressure is applied to a recording
medium on which an image has been output to smooth the image
surface, or the ink on an image surface is heated to be softened
and is flown to give a smooth coating film, for example.
Alternatively, a method of recording an image on an ink jet paper
having a highly glossy surface is also performed.
[0009] The method of applying a pressure to a recording medium on
which an image has been output to smooth the image surface can be
performed on any types of recording media and thus is applicable to
various fields. Japanese Patent Application Laid-Open No.
2013-142794 discloses a gloss generating device used for a printed
matter output from an image forming apparatus using a toner. By the
gloss generating device, the toner image on a recording paper is
heated to be melted, then a smooth surface of a belt is used to
apply a pressure to the melted toner image surface, and then the
toner image is cooled. Consequently, the surface of the toner image
is smoothed, and an image having high glossiness can be obtained.
The gloss generating device is activated on the basis of gloss
information indicating whether or not gloss is developed. After
passing through the gloss generating device, a highly glossy image
substantially equal to a silver halide photograph can be
output.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to providing a transfer
type ink jet recording method and a transfer type ink jet recording
apparatus capable of improving the transferability of an image from
a transfer member to a recording medium and improving the
glossiness of an image formed on a recording medium.
[0011] In view of the above circumstances, the inventors of the
present invention have performed intensive studies, as a result,
have found that the constitution shown below achieves excellent
performances as a transfer type ink jet recording method and a
transfer type ink jet recording apparatus, and have accomplished
the present invention. An aspect of the present invention provides
a transfer type ink jet recording method including:
[0012] a liquid applying step of applying a liquid containing a
first resin to a transfer member,
[0013] an intermediate image forming step of applying, to the
transfer member applied with the liquid, an ink containing a second
resin in such a way as to at least partly overlap with an area
applied with the liquid to thereby form an intermediate image,
[0014] a heating step of heating the intermediate image, and
[0015] a transfer step of transferring the intermediate image
subjected to the heating step to a recording medium.
[0016] In the heating step, the temperature of the intermediate
image is not lower than a minimum coat forming temperature of the
first resin and is not lower than a glass transition temperature of
the second resin, and
[0017] in the transfer step, a temperature of the intermediate
image is lower than a glass transition temperature of the first
resin and is not lower than the glass transition temperature of the
second resin.
[0018] Another aspect of the present invention provides a transfer
type ink jet recording apparatus including:
[0019] a transfer member,
[0020] a liquid applying device configured to apply, to the
transfer member, a liquid containing a first resin,
[0021] an intermediate image forming unit configured to apply, to
the transfer member applied with the liquid, an ink containing a
second resin in such a way as to at least partly overlap with an
area applied with the liquid to thereby form an intermediate
image,
[0022] a heating device configured to heat the intermediate image,
and
[0023] a transfer unit configured to transfer the intermediate
image heated by the heating device to a recording medium.
[0024] The temperature of the intermediate image heated by the
heating device is not lower than a minimum coat forming temperature
of the first resin and is not lower than a glass transition
temperature of the second resin, and
[0025] when the transfer unit allows the intermediate image on the
transfer member to be in contact with the recording medium, a
temperature of the intermediate image is lower than a glass
transition temperature of the first resin and is not lower than the
glass transition temperature of the second resin.
[0026] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a schematic view of a transfer type ink jet
recording apparatus pertaining to an embodiment of the present
invention.
[0028] FIG. 2 is a graph showing the relation between temperature
changes of a glossy layer and transfer operations.
[0029] FIG. 3 is a schematic view of a transfer type ink jet
recording apparatus having a temperature sensor pertaining to an
embodiment of the present invention.
[0030] FIG. 4 is a schematic view of a transfer type ink jet
recording apparatus with a cooling device for a glossy layer
pertaining to an embodiment of the present invention.
[0031] FIG. 5 is a schematic view of an embodiment in which a
transfer roller of the transfer type ink jet recording apparatus
pertaining to the present invention is displaced.
[0032] FIG. 6 is a schematic view of a transfer type ink jet
recording apparatus having a sheet-shaped transfer member in an
embodiment of the present invention.
DESCRIPTION OF THE EMBODIMENTS
[0033] Preferred embodiments of the present invention will now be
described in detail with reference to the accompanying
drawings.
[0034] When a transfer type ink jet recording apparatus is combined
with such a gloss generating device as disclosed in Japanese Patent
Application Laid-Open No. 2013-142794, a printed matter having a
highly glossy image quality substantially equal to silver halide
photographs can be output. A transfer type ink jet recording
apparatus integrated with the gloss generating device unfortunately
has a complicated structure and needs an additional space for the
gloss generating device. Studies by the inventors of the present
invention reveal that when the glossiness of an image is intended
to be improved without the gloss generating device, the
transferability will be degraded unfortunately.
[0035] As disclosed in Japanese Patent Application Laid-Open No.
H07-32721 and International Publication No. WO94/01283, the
transferability of an image can be improved by the transfer type
ink jet recording method using an ink containing a resin that is
softened or melted by heating. However, neither Japanese Patent
Application Laid-Open No. H07-32721 nor International Publication
No. WO94/01283 suggests the application of gloss onto an image
formed on a recording medium. The inventors of the present
invention have studied the ink jet recording methods according to
Japanese Patent Application Laid-Open No. H07-32721 and
International Publication No. WO94/01283 and have found that when
the image transferability is intended to be improved, the
glossiness is likely to deteriorate.
[0036] The inventors of the present invention therefore have
intensively studied a transfer type ink jet recording method and a
transfer type ink jet recording apparatus capable of improving the
glossiness of an image transferred to a recording medium while the
transferability is maintained, without additional use of a gloss
applying device, even with an ink containing a resin that is
softened or melted by heating. As a result, the inventors of the
present invention have obtained novel knowledge that an image
having high transferability and high glossiness can be formed by
transfer to a recording medium while thermal properties of the
resin contained in a liquid used for forming a glossy layer and the
resin contained in an ink used for forming an ink layer are
controlled and temperature conditions of an intermediate image are
controlled in a heating step and a transfer step. The present
invention has been accomplished on the basis of the novel knowledge
by the inventors of the present invention.
[0037] A transfer type ink jet recording method of the present
invention at least includes the following steps (1) to (4). [0038]
(1) A liquid applying step of applying a liquid containing a first
resin to a transfer member. [0039] (2) An intermediate image
forming step of applying, to the transfer member applied with the
liquid, an ink containing a second resin in such a way as to at
least partly overlap with an area applied with the liquid, thereby
forming an intermediate image. [0040] (3) A heating step of heating
the intermediate image. [0041] (4) A transfer step of transferring
the intermediate image subjected to the heating step to a recording
medium.
[0042] In the present invention, by controlling the temperature of
the intermediate image in the heating step and the transfer step
and the thermal properties (the glass transition temperatures and
the minimum coat forming temperatures) of the first resin and the
second resin to particular ranges, both high transferability and
high glossiness are achieved.
[0043] In order to give an image having gloss intended in the
present invention on a recording medium, a glossy layer including a
continuous coating film that forms a face having smoothness for
achieving intended gloss is provided on the image surface. In order
to form the glossy layer, a liquid applying step of applying a
liquid containing a first resin to an image formation surface is
performed as a preceding step of an intermediate image forming
step.
[0044] When an image formed on a recording medium includes an area
where the application of gloss is unnecessary, the first resin
(also called glossy layer-forming material) is not applied to the
region on the image formation surface corresponding to the area
where the application of gloss is unnecessary.
[0045] In the intermediate image forming step, an ink containing a
second resin is applied onto a resin material layer formed from the
first resin applied prior to the ink on the image formation
surface, thereby forming an intermediate image including the resin
material layer and an ink layer covering the resin material
layer.
[0046] The intermediate image forming step may include, in addition
to the ink application step of applying an ink to the image
formation surface, a reaction liquid application step of applying
the reaction liquid described later.
[0047] In the heating step performed between the intermediate image
forming step and the transfer step, the intermediate image is
heated at a temperature not lower than the minimum coat forming
temperature of the first resin and not lower than the glass
transition temperature of the second resin. As a result, an
intermediate image including a glossy layer containing the first
resin and the ink layer as a coating film on the glossy layer is
formed. The glossy layer is formed in contact with the image
formation surface.
[0048] A minimum coat forming temperature is the lower limit
temperature at which a resin is softened and/or melted to form a
continuous coating film that is maintained even in a solidification
state after temperature decrease.
[0049] A combination of the first resin and the second resin is
selected so that the minimum coat forming temperature of the first
resin (T.sub.L-R1), the glass transition temperature of the first
resin (Tg.sub.-R1) and the glass transition temperature of the
second resin (Tg.sub.-R2) satisfy the following relations in the
heating step and the transfer step. [0050] Heating step
[0050] T.sub.L-R1.ltoreq.T.sub.H
Tg.sub.-R2.ltoreq.T.sub.H
(T.sub.H: heating temperature (temperature of intermediate image in
heating step)) [0051] Transfer step
[0051] Tg.sub.-R2.ltoreq.T.sub.GL<Tg.sub.-R1
(T.sub.GL: temperature of glossy layer (temperature of intermediate
image in transfer step))
[0052] The relation between the minimum coat forming temperature of
the first resin (T.sub.L-R1) and the glass transition temperature
of the second resin (Tg.sub.-R2) is not specifically limited, but
when these resins are selected so as to give
Tg.sub.-R2.ltoreq.T.sub.L-R1 and T.sub.H is set to a temperature
not lower than T.sub.L-R1, the above temperature conditions are
satisfied. Such conditions are thus preferred.
[0053] The intermediate image is an extremely thin film, and thus
the temperatures of the ink layer and the glossy layer included in
the intermediate image are substantially equal to the temperature
of the intermediate image. For the same reason, the temperature of
the intermediate image in the heating step is substantially equal
to the surface temperature of the transfer member in the heating
step. The temperature of the intermediate image in the heating step
and the transfer step can be determined by using a noncontact type
thermometer (for example, an infrared thermometer).
[0054] When the first resin is a resin emulsion (also called resin
particles) having a minimum film forming temperature (MFT.sub.-R1)
and a glass transition temperature (Tg.sub.-R1), the above
temperature conditions are as follows. [0055] Heating step
[0055] MFT.sub.-R1<T.sub.H
Tg.sub.-R2<T.sub.H
(T.sub.H: heating temperature (temperature of intermediate image in
heating step)) [0056] Transfer step
[0056] Tg.sub.-R2.ltoreq.T.sub.GL<Tg.sub.-R1
(T.sub.GL: temperature of glossy layer (temperature of intermediate
image in heating step))
[0057] When resin particles having a glass transition temperature
higher than MFT are used as the first resin, MFT can be used in
place of Tg.sub.-R1 as the temperature condition in the transfer
step.
[0058] In order to make the glossy layer into a continuous coating
film layer having a smooth surface for giving intended gloss after
transfer, the liquid applied to the transfer member prior to the
ink contains a coating-formable resin (first resin) as the glossy
layer-forming material. For the purpose, the first resin is
preferably a resin emulsion that easily forms a coating by heating.
When a resin emulsion is used as the first resin, the minimum film
forming temperature is used as the minimum coat forming
temperature. By heating the resin material layer formed from the
resin emulsion applied onto the transfer member at a temperature
not lower than the minimum film forming temperature, resin
particles in an emulsion form contained in the resin material layer
are fused with each other, and a continuous coating film (glossy
layer) can be formed. When the temperature of the resin particles
is not lower than the glass transition temperature during the
heating, the coating film can have higher continuity.
[0059] Hence, when a resin emulsion is used as the first resin, a
resin emulsion having a higher glass transition temperature than
the minimum film forming temperature is preferably used. When the
first resin is a resin emulsion having a higher glass transition
temperature than the minimum film forming temperature, the
temperature of the intermediate image in the heating step is
preferably not lower than the glass transition temperature of the
first resin.
[0060] In addition, together with an improvement in continuity of
the coating film, the resin itself can be softened to improve the
moldability on the image formation surface as the interface of the
glossy layer with the image formation surface. A softened glossy
layer in contact with the transfer member is leveled with the
surface shape of the image formation surface thereof, and the
smoothness of the image formation surface can be reproduced on the
interface of the glossy layer. On this account, the smoothness of
the transfer member surface on which an intermediate image is
formed is important in outputting an image having gloss, and an
image formation surface having sufficient smoothness to give
intended gloss is used.
[0061] To apply the material for forming a glossy layer, a liquid
material is preferred in consideration of handleability and
application simplicity in a series of steps. From this point, the
glossy layer-forming material is also preferably a resin emulsion
containing water as a dispersion medium. In addition, the
formulation of a resin emulsion can be controlled to achieve
sufficient ejection performance for ink jet recording, and thus the
resin emulsion is preferred in consideration that the application
to the image formation surface of the transfer member is performed
by ejection from an ink jet recording head.
[0062] When a liquid resin material is used, various coating
methods, ink jet recording and the like can be used to apply the
liquid resin material to the image formation surface of the
transfer member. When a resin material is prepared with a liquid
medium such as water and a resin material layer is formed by
drying, a liquid component evaporates from the resin material layer
by any application method. Due to the evaporation, the resin
contained in a resin material layer may not be uniformly present in
the resin material layer. For example, a liquid component is
removed by treatment including heating to form voids, and the voids
may be non-uniformly left in the resin material layer, or
unevenness may be non-uniformly formed on the surface of a resin
material layer. In such a case, the continuity of a coating film or
the smoothness of the surface may be impaired. If transfer to a
recording medium is performed while the surface of a resin material
layer on the image formation face still has non-uniform unevenness,
the unevenness on the surface is maintained on the image surface to
cause uneven glossiness. In order to solve the uneven glossiness,
the heating step is performed before the transfer step to allow the
first resin contained in the resin material layer to soften or
flow, and the coating formability and the smooth surface
formability are improved.
[0063] The temperature of the intermediate image in the heating
step can be set depending on the first resin, the second resin, the
structure of a recording apparatus or the like so as to satisfy the
temperature conditions relating to the first resin and the second
resin. The temperature of the intermediate image in the heating
step is not limited to particular values, but is preferably
80.degree. C. or more to 200.degree. C. or less and more preferably
90.degree. C. to 150.degree. C.
[0064] When a resin emulsion is used as the glossy layer-forming
material and the temperature of a resin material layer formed by
using the resin emulsion becomes equal to or higher than the
minimum film forming temperature, the resin particles are fused
with each other to form a continuous coating film, and concurrently
the formed coating film is softened to exhibit deformability or
flowability. Hence, the coating film reproduces the image formation
surface of the transfer member on the interface with the image
formation surface, thus the smoothness of the image formation
surface is transferred to the interface of the coating film with
the image formation surface, and a glossy layer can be formed
before transfer. As a result, the outermost layer of an image after
transfer can be a glossy layer including a continuous coating film
having a smooth surface, and the image can have gloss. The minimum
coat forming temperature (minimum film forming temperature) of the
first resin can be measured in accordance with the test method
described in JIS K 6828-2:2003 (Synthetic resin emulsion Part 2:
Determination of white point temperature and minimum film forming
temperature). In the Examples described below, measurement of a
minimum film forming temperature was effected using a minimum film
forming temperature bar (trade name: MFFTB-60; manufactured by
Rhopoint Instruments). The minimum coat forming temperature of the
first resin is preferably 50.degree. C. or more to 90.degree. C. or
less and more preferably 55.degree. C. or more to 85.degree. C. or
less. Moreover, the minimum film forming temperature of the first
resin is preferably 50.degree. C. or more to 90.degree. C. or less
and more preferably 55.degree. C. or more to 85.degree. C. or
less.
[0065] The glossy layer-forming material may contain an additive
having a certain melting point and usable to form a glossy layer,
such as wax. When the first resin is used in combination with wax,
the temperature of the intermediate image in the heating step is
preferably not lower than the minimum coat forming temperature of
the first resin and is preferably not lower than the melting point
of the wax. By controlling the temperature of the intermediate
image in the heating step as above, the flowability of the wax is
immediately increased and the resin material layer for forming a
glossy layer on the interface with the image formation surface of
the transfer member can be rapidly and easily uniformized. In the
subsequent process in which heating is turned off to decrease the
temperature and the temperature of the glossy layer becomes lower
than the melting point of the wax, the wax immediately solidifies
while maintaining the uniformity, and this also effectively
improves the releasability between the glossy layer and the image
formation surface of the transfer member at the time of transfer.
Hence, the temperature of the intermediate image in the transfer
step is preferably lower than the glass transition temperature of a
first resin and lower than the melting point of a wax.
[0066] The ink to form an intermediate image contains a second
resin. When the heating is turned off to perform transfer, the
temperature of the intermediate image can be controlled to meet the
above conditions. In other words, as for the control of the
temperature of the intermediate image, the temperature of the
intermediate image can be controlled directly in the transfer step
or can be controlled in an additional temperature control step of
controlling the temperature of an intermediate image subjected to
the heating step and to be subjected to the transfer step. After
this temperature control, the glossy layer forms a smooth
continuous coating film and solidifies, but the ink layer as a
coating film to come into contact with a recording medium maintains
a softened state. Hence, when the intermediate image is being
released from the transfer member, the surface of a recording
medium is unlikely to be roughened and thus the image transferred
to the recording medium can have a high glossiness. The ink layer
as a coating film can have an appropriate adhesiveness for transfer
to a facing recording medium and thus can achieve high
transferability.
[0067] In order to help the control of the temperature of the
intermediate image in the transfer step to the above range, the
intermediate image is preferably cooled between the heating step
and the transfer step. In other words, a cooling step of cooling an
intermediate image is preferably included. The cooling of an
intermediate image is preferably performed by at least one of
natural air cooling and a cooling device and is more preferably
performed by both natural air cooling and a cooling device.
[0068] When an image is transferred to a recording medium through
the above steps, the outermost face of the image transferred onto
the recording medium has a glossy layer. The surface of the glossy
layer after transfer is a face having smoothness for giving an
intended gloss. The smooth surface is formed by using the softening
of the first resin by heating and thus the smoothness of the image
formation surface of the transfer member in contact therewith is
transferred to the surface of the glossy layer after transfer.
Hence, the smoothness of the image formation surface can be
selected depending on an intended gloss. Studies by the inventors
of the present invention have revealed that in order to achieve a
glossiness substantially equal to silver halide photographs, the
smoothness of the outermost face of an image is preferably made to
be a surface roughness Ra of 0.1 .mu.m or less. On the transfer
member, therefore, the image formation surface on which a glossy
layer is to be provided also preferably has a surface roughness
(also called surface roughness of a transfer member) Ra of 0.1
.mu.m or less. The lower limit of the surface roughness of the
transfer member is 0 .mu.m.
[0069] The thickness of the glossy layer is preferably controlled
within a range from 1/2 of the thickness of the ink layer included
in an image to substantially the same thickness as the ink
layer.
[0070] To transfer an image, a pressure is applied to a transfer
member and a recording medium and thus the surface unevenness
degree of the recording medium may affect the smoothness of the
transferred image surface. When a common printing paper is used to
print a highly glossy image, a recording medium having a
comparatively small surface unevenness, or a coating paper is
usually used. For a photograph image, a thick printing paper is
typically used. In consideration of such circumstances, the
recording medium is preferably a cast-coated paper or a gloss
coated paper. Examples of the cast-coated paper include Gloria Pure
White (trade name, manufactured by GOJO PAPER MFG. CO., LTD.) and
Mirror Coat-Gold (trade name, manufactured by Oji Paper Co., Ltd.).
A thick paper having a basis weight of 127.9 g/m.sup.2 or more is
preferred.
[0071] In the above description, a glossy layer having a high
smoothness is provided on the surface of a transferred image to
achieve high glossiness substantially equal to silver halide
photographs. Output images, however, do not need high glossiness in
some cases. In such a case, the liquid containing a first resin is
not applied to the image formation surface, but an ink layer as a
coating film can be formed as the surface of a transferred image.
Before transfer, the ink layer as a coating film is in contact with
the image formation surface of the transfer member in which the
surface unevenness is controlled to have such smoothness as to
achieve gloss, but the transfer is performed at a temperature not
lower than the glass transition temperature of a second resin in
the ink and thus the ink layer as a coating film in a softened
state is released from the image formation surface of the transfer
member. In other words, the ink layer as a coating film is still in
a softened state after transfer onto a recording medium, thus the
smoothness is difficult to maintain on the surface of the
transferred image and no gloss is applied to the image surface.
[0072] When an output image does not need application of gloss by a
glossy layer, only the liquid applying step of applying a liquid
containing a material (first resin) for forming a glossy layer is
not executed, but the other steps are performed. Consequently,
image formation without execution of gloss application can be
performed. In other words, the gloss application can be selected by
further adding a liquid application selecting step (also called
gloss application selecting step) of selecting "execution" or
"non-execution" of the application of the glossy layer-forming
material- (first resin-) containing liquid. In particular, when the
glossy layer-forming material-containing liquid is applied with an
ink jet recording head, only whether or not a driving signal is
sent to the corresponding ink jet recording head can be switched to
select the application of gloss, and thus the selection is simple.
A switching signal can be sent before image signals are sent to an
ink jet recording head group.
[0073] The transfer type ink jet recording apparatus pertaining to
the present invention at least includes a transfer member, a liquid
applying device (also called resin material applying device), an
intermediate image forming unit, a heating device and a transfer
unit.
[0074] The resin material applying device includes a resin material
applying unit configured to apply a liquid containing a first resin
for forming a glossy layer to an image formation surface of the
transfer member, forming a resin material layer.
[0075] The intermediate image forming unit includes an ink applying
unit configured to apply an ink containing a second resin by an ink
jet method to the image formation surface with the resin material
layer, forming an intermediate image including the resin material
layer and an ink layer covering the resin material layer. The ink
applying unit can include an ink jet device having a recording head
that ejects an ink.
[0076] The intermediate image forming unit may include a reaction
liquid applying unit configured to apply the reaction liquid
described later to the image formation surface.
[0077] With the heating device, the intermediate image formed on
the image formation surface and including the resin material layer
and the ink layer covering the resin material layer is heated to a
temperature not lower than the minimum coat forming temperature of
the first resin and not lower than the glass transition temperature
of the second resin, forming a glossy layer as a coating film
containing the first resin and an ink layer as a coating film on
the glossy layer or an intermediate image having a multilayer
structure of these coating films.
[0078] The transfer type ink jet recording apparatus may include a
temperature controlling unit. The temperature controlling unit is a
unit to control the temperature of the intermediate image including
the glossy layer and the ink layer after heating with the heating
device so as to satisfy the above temperature conditions in the
transfer step. In other words, with the temperature controlling
unit, temperature control is performed so that the temperature of
the glossy layer containing the first resin included in the
intermediate image formed by heating with the heating device
reaches a temperature lower than the glass transition temperature
of the first resin and not lower than the glass transition
temperature of the second resin. In other words, with the
temperature controlling unit, temperature control is performed so
that the temperature of the intermediate image after heating with
the heating device becomes lower than the glass transition
temperature of the first resin and equal to or higher than the
glass transition temperature of the second resin. The transfer
member subjected to the temperature control is sent to the transfer
unit, and the intermediate image on the transfer member is treated
in the following transfer step. The temperature controlling unit
preferably includes a cooling device. When a transfer unit also
serves as a temperature controlling unit, a temperature controlling
unit is not necessarily required except in the transfer unit.
[0079] The application of the first resin- (glossy layer-forming
material-) containing liquid to the image formation surface of the
transfer member can be performed on the whole image formation
surface or on a region of the image formation surface selected
corresponding to a glossy layer partly applied to an image on a
recording medium.
[0080] A controlling unit for selecting "execution" or
"non-execution" of the application of the first resin- (glossy
layer-forming material-) containing liquid to the image formation
surface of the transfer member may be provided. The control of the
resin material applying device by the controlling unit can be set
by an instruction based on a previously set program, an instruction
manually input by a user of the apparatus or the like.
[0081] The image formation surface of the transfer member is
conveyed relative to the above units, and each unit works in such a
way as to be synchronized with the conveyance of the image
formation surface. Consequently, an image having an intended gloss
can be formed on a recording medium when needed.
[0082] An example recording apparatus using the transfer type ink
jet recording method pertaining to an embodiment of the present
invention and an outline of the operation will next be
described.
[0083] FIG. 1 is a schematic view showing an example structure of a
transfer type ink jet recording apparatus of the present invention.
The apparatus shown in the figure includes a transfer member 1, a
reaction liquid applying device 3, an ink jet recording head group
4, a heater 6 as a heating device and a transfer roller 71 (also
called pressure roller) and a rear support roller 72 included in a
transfer unit.
[0084] In the transfer member 1, an image formation surface (not
shown) is bonded to the outer surface of an endless belt formed
from a rolled steel with a double-sided adhesive tape, and the belt
is stretched and supported on a pair of rotatable,
cylindrical-shaped support rollers 21 and 22. The image formation
surface of the transfer member 1 is conveyed by a conveyance device
including the support rollers 21 and 22. To the support rollers 21
and 22, a driving motor (not shown) for conveying the endless belt
is attached. The ink jet recording head group 4 includes an ink jet
recording head 41 for forming a resin material layer and ink jet
recording heads 42 to 45 for forming an ink layer. In the apparatus
shown in the figure, a reaction liquid applying device constituting
a reaction liquid applying unit and the ink jet device constituting
an ink applying unit constitute an intermediate image forming unit.
In the apparatus shown in the figure, a reaction liquid coating
device 3 is provided as the reaction liquid applying device.
[0085] At the downstream side in the conveyance direction of the
image formation surface from the ink jet recording head group 4, a
hot air dryer 5 as a heating device for evaporating and removing
liquid components contained in an intermediate image 9 is
provided.
[0086] The heater 6 as a heating device for making a resin material
layer and an ink layer into coating films is integrated in the
support roller 22. A recording medium 8 to which an intermediate
image is transferred is inserted into a nip that is formed between
the transfer roller 71 and the rear support roller 72 supporting a
pressure from the transfer roller 71 on the back surface of the
recording medium 8, together with the image formation surface
having an intermediate image, and the image is transferred.
[0087] Next, the operation to form an image having a glossy layer
on a recording medium 8 by using a transfer type ink jet recording
apparatus having the structure in FIG. 1 will be described. As the
support rollers 21 and 22 rotate, the endless belt is conveyed, or
the transfer member 1 is conveyed first. Accordingly, the image
formation surface of the transfer member 1 is sequentially conveyed
to each treatment region. Each device arranged in the periphery
works in such a way as to be synchronized with the conveyance of
the image formation surface.
[0088] First, to the image formation surface of the transfer member
1, the reaction liquid coating device 3 applies a reaction liquid.
The reaction liquid used here is a liquid for improving the
fixability of an image. As the reaction liquid, a liquid capable of
increasing the viscosity of an ink or an ink viscosity increasing
liquid can be preferably used. By applying the reaction liquid and
an ink to the image formation surface in such a way as to give a
region in which the reaction liquid and the ink at least overlap
with each other, the effect by application of the reaction liquid
can be obtained. The reaction liquid and the ink are applied in any
order, but the reaction liquid is preferably applied to the
transfer member 1 before the application of the ink. The ink
viscosity increasing effect by the reaction liquid will be
described later. An appropriate amount of the reaction liquid 31
stored in a storage container 32 is drawn by the rotation of a
fountain roller 33 and then is loaded in cells formed on the
peripheral surface of an anilox roller 34 that is in contact with
the fountain roller 33 and rotates. The reaction liquid overloaded
in the cells is scraped off by a doctor blade 35 that is in contact
with the anilox roller surface and is returned into the storage
container 32. In addition, the anilox roller 34 is in contact with
the transfer member 1 and thus the reaction liquid in the cells are
transferred onto the surface of the transfer member 1.
[0089] As the support rollers 21, 22 rotate, the image formation
surface of the transfer member 1 applied with the reaction liquid
reaches a treatment region with the ink jet recording head group 4.
The ink jet recording head 41 first applies a liquid containing a
first resin (glossy layer-forming material) to the whole region on
the image formation surface, and a resin material layer is formed
on the image formation surface. In the apparatus shown in the
figure, a resin emulsion is used as the glossy layer-forming
material contained in the liquid. Resin particles contained in the
resin emulsion are formed from a first resin.
[0090] The resin emulsion is applied from the ink jet recording
head as liquid drops to the image formation surface. The applied
glossy layer-forming material is formed from the resin emulsion and
thus is arranged in a dot pattern or an island pattern on the image
formation surface. The resin emulsion arranged in a dot pattern or
an island pattern spreads as a liquid on the image formation
surface with time and dots and/or islands come into contact with
each other at many points. Hence, at the time of the subsequent
heat treatment, resin particles included in the resin emulsion are
fused to each other to form a film, and a coating film is likely to
be formed. In other words, a coating film as a glossy layer is
formed.
[0091] Each dot portion and each island portion may be formed from
a single liquid drop including a glossy layer-forming material or
from a plurality of liquid drops.
[0092] The image formation surface is previously applied with the
reaction liquid, but liquid drops of the resin emulsion reaches the
image formation surface to form a resin material layer that is in
contact with the image formation surface of the transfer
member.
[0093] The image formation surface of the transfer member 1 is
conveyed to the ink applying unit and inks are applied by ink jet
recording heads 42, 43, 44, 45 to form an intermediate image (ink
image). From these ink jet recording heads, black, cyan, magenta
and yellow inks are selectively ejected in response to image
signals. The reaction liquid 31 on the transfer member 1 is reacted
with these inks to form an intermediate image 9 (ink image)
including an ink layer having a higher viscosity on the transfer
member 1.
[0094] As described above, onto the image formation surface of the
transfer member, the reaction liquid, the glossy layer-forming
material and the ink are applied in this order, and on the transfer
member, the ink layer is present on the resin material layer. As
mentioned above, the adjacent resin material layer contains voids,
thus through the voids, the reaction liquid can come into contact
with the ink, and components in the reaction liquid can cause
viscosity increase of the ink. In other words, many voids are
formed in the resin material layer and thus the resin material
layer does not interfere with the contact between the ink and the
reaction liquid.
[0095] On the ink layer formed on the image formation surface of
the transfer member, a transfer assisting agent for assisting
transfer may be additionally applied. By applying the transfer
assisting agent, the transferability of an image from a transfer
member to a recording medium can be further improved.
[0096] The intermediate image 9 next passes under the hot air dryer
5, where liquid components such as water in the ink layer is
removed by hot air and concurrently the ink layer and the resin
material layer in the intermediate image 9 are also preliminarily
heated.
[0097] As the transfer member 1 is further conveyed, the
intermediate image 9 formed on the image formation surface of the
transfer member 1 is heated by the heater 6 integrated in the
support roller 22. This heating is performed from the transfer
member 1 by heat transfer through the endless belt in a contact
manner. In the heating, both the resin material layer and the ink
layer are extremely thin layers, and thus the resin material layer
and the ink layer are heated at substantially the same temperature.
In the present embodiment, a resin emulsion is used as the glossy
layer-forming material, and by the above heating, the resin
material layer can be heated at a temperature not lower than the
minimum film forming temperature of the resin emulsion. A resin
emulsion typically has a higher glass transition temperature than
the minimum film forming temperature, but the heating enables the
resin to soften when the resin particles in the resin material
layer are fused and concurrently enables the formation of a coating
film along the smooth face of the image formation surface of the
transfer member 1. Meanwhile, when a second resin having a glass
transition temperature lower than the minimum film forming
temperature of the resin emulsion of the first resin is used, the
temperature of the heating device is set to a temperature higher
than the minimum film forming temperature of the resin emulsion.
The heating at this temperature setting enables the resin particles
in the resin material layer to form a coating film of a glossy
layer and enables the second resin to form a coating film of an ink
layer to improve mechanical strength and adhesive power to a
recording medium.
[0098] Through the heating, the intermediate image is conveyed
toward the transfer step with the transfer unit. By providing a
heat radiation region included in a temperature controlling unit
between the heating step with the heating device 6 and the transfer
step with the transfer unit, the temperature of a laminated body of
the glossy layer and the ink layer as a coating film gradually
decreases to reach a temperature lower than the glass transition
temperature of the first resin. The position of the transfer roller
7 is controlled so that the temperature of the glossy layer is
lower than the glass transition temperature of the first resin and
is higher than the glass transition temperature of the second resin
in the ink layer as a coating film when the intermediate image
reaches the transfer roller 71.
[0099] At this time, the glossy layer included in the intermediate
image is in the solid state, but the ink layer as a coating film is
still in a softened state. The ink layer as a coating film included
in the intermediate image and coming into contact with the
recording medium 8 is still softened, and thus a sufficient
adhesiveness for transfer can be imparted to an image to be
transferred.
[0100] In the step, the ink layer as a coating film included in the
intermediate image is stacked on the surface of the recording
medium 8, and a certain pressure is applied to transfer the image.
The image transferred onto the recording medium has the glossy
layer on the outermost surface and thus has a smooth surface that
is sufficient for gloss and is imparted by the smoothness of the
image formation surface of the transfer member, and an image having
an intended gloss can be formed. The transfer roller 71 included in
the transfer unit has such a structure as to follow the conveyance
of the image formation surface of the transfer member 1 and to
apply a pressure while the rear support roller 72 supports the rear
surface of the image formation surface of the transfer member
1.
[0101] A part of the image formation surface of the transfer member
1 having completed the transfer is cleaned by a cleaning mechanism
provided as needed and not shown in drawings, and then is returned
to the position to come into contact with the reaction liquid
coating device 3. The series of operations are restarted, and the
transfer member 1 is repeatedly used.
[0102] Next, each component of a transfer type ink jet recording
apparatus pertaining to an embodiment of the present invention,
each step in the image formation, each material used for the image
formation and the like will be described.
[0103] <Transfer Member>
[0104] A transfer member has an image formation surface that serves
as a substrate for forming an intermediate image and is for forming
an intermediate image. The transfer member may have a structure
depending on a purpose, such as a single layer structure including
the same material, a multilayer structure having a surface layer
and an elastic layer and a multiple structure having a surface
layer, an elastic layer and a compressible layer. Each layer in the
multilayer structure may include a single layer or multiple
layers.
[0105] The transfer member may be supported on a support.
[0106] The support can be formed from a material that supports the
transfer member and functions to transmit a required force to the
whole transfer member. From the viewpoint of the conveyance
accuracy and the durability thereof, the material of the support
member is preferably metals, ceramics or resins, for example.
Specifically, the following materials are preferred in terms of the
rigidity capable of withstanding the pressure at the time of
transfer, dimensional accuracy and characteristics required to
reduce inertia during operation to improve the control
responsivity. In other words, aluminum, iron, stainless steel,
acetal resins, epoxy resins, polyimide, polyethylene, polyethylene
terephthalate, nylon, polyurethane, silica ceramics, alumina
ceramics and the like are preferred. These materials may be used in
combination.
[0107] The transfer member preferably has an elasticity required
for transfer in order to perform pressure bonding of an
intermediate image to a recording medium such as paper and to
transfer the image. When paper is used as the recording medium, the
hardness of the transfer member is preferably a Durometer-A
hardness (in accordance with JIS K6253) of 10 to 100 and more
preferably 20 to 60. When a transfer member has a single layer
structure, the whole single layer preferably has a hardness within
the above range. When a transfer member has a multilayer structure
including an elastic layer, the elastic layer preferably has a
hardness within the above range.
[0108] The material of the transfer member satisfying the above
hardness can be selected from materials capable of forming an
intermediate image forming surface that enables the formation of an
intermediate image and the transfer to a recording medium, and
resins, ceramics, metals and various materials can be appropriately
used. From the viewpoint of processing characteristics and the
above elasticity property, various rubber material and elastomer
materials can be preferably used. Examples of the rubber material
include polybutadiene rubbers, nitrile rubbers such as
nitrile-butadiene rubber, chloroprene rubbers, silicone-type
rubbers such as silicone rubber, fluorocarbon rubbers such as
fluororubber and urethane-type rubbers such as urethane rubber.
Examples of the elastomer material preferably include styrenic
elastomers, olefinic elastomers, polyvinyl chloride elastomers,
ester elastomers and amide elastomers. Polyether, polyester,
polystyrene, polycarbonate, siloxane compounds and perfluorocarbon
compounds can also be preferably used, for example. In particular,
nitrile-butadiene rubber, silicone rubber, fluororubber and
urethane rubber are particularly preferably used from the viewpoint
of dimensional stability, durability, heat resistance and the like.
A transfer member formed from a composite material mixed with
different materials in the above can be suitably used. Examples of
such a composite material include a laminate material prepared by
coating an endless belt-shaped urethane rubber with silicone
rubber, a sheet prepared by laminating silicone rubber on a
polyethylene terephthalate film and a laminate material prepared by
forming a film of a polysiloxane compound on a urethane rubber
sheet. As the composite material, a sheet prepared by infiltrating
a rubber material such as nitrile-butadiene rubber and urethane
rubber into a woven fabric such as a cotton fabric, a polyester
fabric and a rayon fabric as a base fabric can also be suitably
used.
[0109] The image formation surface of the transfer member may be
subjected to an appropriate surface treatment. Examples of such a
surface treatment include a flame treatment, a corona treatment, a
plasma treatment, a polishing treatment, a roughening treatment, an
active energy ray (UV, IR, RF, for example) irradiation treatment,
an ozone treatment, a surfactant treatment and a silane coupling
treatment. These treatments are also preferably performed in
combination.
[0110] The surface of a glossy layer formed on the image surface
transferred onto a recording medium has such a smoothness as to
achieve an intended gloss, and the smoothness is defined by the
smoothness of the image formation surface of a transfer member.
Hence, the image formation surface of the transfer member is formed
as a face having the smoothness capable of imparting an intended
gloss to the surface of an image transferred to a recording medium.
In order to achieve gloss substantially equal to silver halide
photographs on an image transferred to a recording medium, the
smoothness of the image formation surface of the transfer member is
preferably made to be a surface roughness Ra of 0.1 .mu.m or
less.
[0111] Each of the support and the transfer member may be formed by
using a single material or a plurality of different materials. Each
of the support and the transfer member may have a single layer
structure or a multilayer structure. Various adhesives,
double-sided adhesive tapes and the like may be present for
fixing/holding such members.
[0112] Examples of the shape of the transfer member include a sheet
shape, a roller shape, a drum shape and a belt shape. When a
belt-shaped transfer member is used as an endless belt, the same
transfer member can be continuously, repeatedly used, and thus such
a structure is particularly preferred in terms of productivity of
images. The dimensions of the transfer member can be appropriately
set depending on the size of an intended image.
[0113] <Reaction Liquid>
[0114] The reaction liquid contains a component that increases the
viscosity of an ink (ink viscosity-increasing component). Here, the
increase in viscosity of an ink is such a phenomenon that a
coloring material, a resin or another component included in an ink
comes into contact with an ink viscosity-increasing component and
the component is chemically reacted or physically adsorbed to
increase the viscosity of an ink or to causes an increase in
viscosity. The increase in viscosity of an ink includes not only an
increase in viscosity of an ink but also a local increase in
viscosity by aggregation of some of the components included in an
ink, such as a coloring material and a resin.
[0115] The ink viscosity-increasing component has the effect of
lowering the flowability of an ink and/or some components included
in an ink on a transfer member to suppress bleeding or beading when
an intermediate image is formed.
[0116] As the ink viscosity-increasing component contained in the
reaction liquid, polyvalent metal ions, organic acids, cation
polymers and porous microparticles can be used, for example.
Specifically preferred are polyvalent metal ions and organic acids.
A plurality of types of ink viscosity-increasing components can
also be preferably contained. The content of the ink
viscosity-increasing component in the reaction liquid is preferably
5% by mass or more relative to the total mass of the reaction
liquid.
[0117] Examples of the metal ion usable as the ink
viscosity-increasing component include divalent metal ions such as
Ca.sup.2+, Cu.sup.2+, Ni.sup.2+, Mg.sup.2+, Sr.sup.2+, Ba.sup.2+
and Zn.sup.2+ and trivalent metal ions such as Fe.sup.3+,
Cr.sup.3+, Y.sup.3+ and Al.sup.+. Examples of the organic acid
usable as the ink viscosity-increasing component include oxalic
acid, polyacrylic acid, formic acid, acetic acid, propionic acid,
glycolic acid, malonic acid, malic acid, maleic acid, ascorbic
acid, levulinic acid, succinic acid, glutaric acid, glutamic acid,
fumaric acid, citric acid, tartaric acid, lactic acid, pyrrolidone
carboxylic acid, pyrone carboxylic acid, pyrrole carboxylic acid,
furan carboxylic acid, pyridine carboxylic acid, coumaric acid,
thiophene carboxylic acid, nicotinic acid, oxysuccinic acid and
dioxysuccinic acid.
[0118] As the ink viscosity-increasing component, one of or a
combination of two or more of components selected from the above
components can be used as needed.
[0119] The reaction liquid may contain an appropriate amount of
water or an organic solvent. The water used in this case is
preferably a deionized water prepared by ion exchanging, for
example. The organic solvent usable in the reaction liquid is not
limited to particular solvents and any known water-soluble organic
solvent can be used.
[0120] To the reaction liquid, various resins can also be added in
order to improve the transferability or to improve the toughness of
an image finally formed. By adding a resin, the adhesiveness of an
intermediate image to a recording medium at the time of transfer
can be increased, or the mechanical strength of a transferred image
after transfer to a recording medium can be increased. Depending on
the type of a resin, the water resistance of an image may be
improved. The resin added to the reaction liquid can be a resin
that does not aggregate by an ink viscosity-increasing component in
the reaction liquid, can coexist with an ink viscosity-increasing
component and have the above intended function. The resin used for
such a purpose can be contained in the reaction liquid in a
dissolved state, an emulsion state or a suspension state. A
surfactant or a viscosity modifier can be added to appropriately
control the surface tension or the viscosity thereof.
[0121] As the resin contained in the reaction liquid, a resin
capable of providing the above advantageous effect can be selected
from the glossy layer-forming resins exemplified later depending on
the type of an ink viscosity-increasing component.
[0122] The amount of the resin can be selected from a range of 0.5%
by mass or more to 15.0% by mass or less relative to the total mass
of the reaction liquid.
[0123] <Reaction Liquid Application Method>
[0124] As the method of applying the reaction liquid to the surface
of the transfer member, various known methods can be appropriately
used. Examples of the method include die coating, blade coating,
gravure coating, gravure offset coating, wire-bar coating and spray
coating. The application method using an ink jet recording head by
the ink jet method is also preferred. A combination of a plurality
of methods is also particularly preferred. The reaction liquid can
be applied to the image formation surface of the transfer member
before ink application and/or after ink application. In order to
further stabilize an intermediate image or to further increase the
improvement effect of the transferability, the reaction liquid is
preferably applied to the image formation surface of the transfer
member before ink application. The reaction liquid is preferably
applied to the image formation surface so that a reaction liquid
application region at least partly overlaps with an ink application
region.
[0125] <Glossy Layer-Forming Material (First Resin)>
[0126] The glossy layer-forming material is preferably capable of
forming a colorless, transparent glossy layer that does not affect
an image. Here, "colorless, transparent" means that a glossy layer
is such a colorless state and has such an optical transparency as
not to affect the image quality such as an image density, a hue and
a resolution of an image covered with the glossy layer. Hence, the
glossy layer-forming material is preferably prepared from
components free from coloring materials. When a component free from
coloring materials as the glossy layer-forming material has
colorability to some extent but can form a glossy layer that does
not affect an image, such a component can be used.
[0127] The first resin used as the glossy layer-forming material
may be any resin that is usable to form a glossy layer as a
continuous coating film having a smooth surface capable of
imparting gloss to the surface of an image transferred to a
recording medium. Specific examples of the first resin include
polyolefins such as polyethylene, polypropylene, polyisobutylene,
oxidized polyethylene, polytetrafluoroethylene, ethylene-acrylic
acid copolymers, ethylene-ethyl acrylate copolymers and
ethylene-vinyl acetate copolymers. Additional examples include
homopolymers such as polystyrene, polyurethane, polyester,
polyether, polyurea, polyamide, polyvinyl alcohol,
poly(meth)acrylic acid and salts thereof, polyalkyl (meth)acrylate
and polydiene, copolymers of two or more monomers for these
homopolymers and derivatives thereof. Specifically preferred is an
acrylic resin or a urethane resin. Specifically preferred is an
acrylic resin or a urethane resin.
[0128] The acrylic resin is specifically preferably a copolymer at
least having a hydrophilic unit and a hydrophobic unit as
constitutional units as exemplified below.
[0129] Examples of the monomer having a hydrophilic group and
giving a hydrophilic unit by polymerization include the following
monomers. Examples include acidic monomers having a carboxy group,
such as (meth)acrylic acid, itaconic acid, maleic acid and fumaric
acid; acidic monomers having a phosphonic acid group, such as
(meth)acrylic acid-2-ethyl phosphonate; anionic monomers including
anhydrides and salts of these acidic monomers; monomers having a
hydroxy group, such as 2-hydroxyethyl (meth)acrylate and
3-hydroxypropyl (meth)acrylate; and monomers having an ethylene
oxide group, such as methoxy(mono, di, tri, poly)ethylene glycol
(meth)acrylates. Examples of the cation constituting a salt of an
anionic monomer include a lithium ion, a sodium ion, a potassium
ion, an ammonium ion and organic ammonium ions. The resin is
preferably a resin that exhibits water-solubility when neutralized
with a neutralizer such as hydroxides of alkali metals (for
example, lithium, sodium and potassium) and aqueous ammonia.
[0130] Examples of the monomer having a hydrophobic group and
giving a hydrophobic unit by polymerization include the following
monomers. Examples include monomers having an aromatic ring, such
as styrene, a-methylstyrene and benzyl (meth)acrylate; and monomers
having an aliphatic group, such as ethyl (meth)acrylate, methyl
(meth)acrylate, (n-, iso-)propyl (meth)acrylates, (n-, iso-,
t-)butyl (meth)acrylates and 2-ethylhexyl (meth)acrylate.
[0131] The urethane resin is preferably a resin prepared by
reaction of a polyisocyanate with a polyol and may be a resin
prepared by reaction further using a chain extender. Examples of
the polyisocyanate include aliphatic, alicyclic, aromatic and
aromatic-aliphatic polyisocyanates. Examples of the polyol include
polyester polyols, polyether polyols and polycarbonate polyols, and
such a polyol may additionally have an acid group. In the present
invention, both a polyether polyol and a diol having an acid group
are preferably used as the polyol and the acid value of a urethane
resin can be controlled by the proportion of a diol having an acid
group. The chain extender is a compound that reacts with a
remaining isocyanate group that fails to form a urethane bond, in
the polyisocyanate units of the urethane prepolymer prepared by
reacting a polyisocyanate and a polyol.
[0132] The first resin preferably has a weight average molecular
weight of 1,000 or more to 2,000,000 or less.
[0133] When the first resin is dissolved or dispersed in water or
in a liquid medium containing water and various additives to
prepare a glossy layer-forming material-containing liquid, the
amount of the first resin in the liquid is preferably 1% by mass or
more to 50% by mass or less and more preferably 2% by mass or more
to 40% by mass or less relative to the total mass of the liquid
material.
[0134] A glossy layer is prepared by heating the first resin in the
heating step at a temperature not lower than the minimum coat
forming temperature of the first resin into a uniform, continuous
coating film and is required to have such a surface smoothness as
to achieve intended gloss. Meanwhile, on the transfer member before
transfer, the glossy layer is in contact with the image formation
surface of the transfer member and thus is required to be smoothly
released from the transfer member and to be in a uniform film state
at the time of transfer. From these viewpoints, the glossy
layer-forming material is preferably a resin emulsion prepared by
dispersing resin particles formed of a first resin in a liquid
medium containing water and the like. By using the resin emulsion
as the glossy layer-forming material, film forming characteristics
in association with fusion of resin particles can be used to form a
glossy layer satisfying the above requirement. The first resin
preferably has a glass transition temperature of 70.degree. C. or
more to 110.degree. C. or less and more preferably 80.degree. C. or
more to 100.degree. C. or less.
[0135] In consideration of releasability of an image from the
transfer member at the time of transfer, the glossy layer-forming
material may contain a wax that is immediately liquefied by heating
at a temperature not lower than the melting point thereof and is
immediately solidified at a temperature lower than the melting
point.
[0136] Specific examples of the wax include carnauba wax, paraffin
wax, Sasol wax, microcrystalline wax, castor wax and polyethylene
wax. These waxes can be used singly or in combination of two or
more of them.
[0137] The amount of the wax can be selected from a range of 1% by
mass or more to 50% by mass or less relative to the total mass of
the glossy layer-forming material.
[0138] In order to control the coating-forming temperature (the
minimum film forming temperature for a resin emulsion), a known
film formation assisting agent, a fusing delaying agent or the like
may be added as needed.
[0139] In consideration of ejection by an ink jet recording head,
use of water as the main component in a solvent for preparing a
liquid material helps the ejection as with a typical ink for ink
jet. When the above resin is a water-insoluble resin in such a
case, an emulsion of the resin dispersed in a liquid is preferably
used. In this case, the minimum film forming temperature of the
resin emulsion is used as the coating-forming temperature. By
heating the resin material layer formed from the resin emulsion at
a temperature not lower than the minimum film forming temperature
thereof, resin particles of the emulsion are fused to each other to
form a continuous coating film as a glossy layer. Hence, the resin
emulsion is particularly preferably used in order to make the
outermost surface of an image finally formed on a recording medium
into a smooth surface required to achieve intended gloss.
[0140] <Application Method of Glossy Layer-Forming Material
(First Resin)>
[0141] The application method of the glossy layer-forming material
to the transfer member may be any method capable of forming an
intended resin material layer. Various methods including an
ejection method with an ink jet recording head, various coating
methods and a method of planar migration or transfer of a thin
layer can be used.
[0142] When a difference in gloss is intended to be expressed on
the same image, the method using an ink jet recording head enables
an arrangement of a resin material layer by, for example, varying
the application amount of the glossy layer-forming material with
regions.
[0143] <Intermediate Image Formation>
[0144] Onto the image formation surface of the transfer member
applied with the reaction liquid, an ink jet recording head is used
to apply an ink in response to image signals. A transfer assisting
liquid for assisting transfer may be additionally applied onto the
ink layer.
[0145] The operation manner of the recording head is not limited to
a particular manner. For example, what is called a shuttle type ink
jet recording head in which a head is swept in a direction
orthogonal to the moving direction of a transfer member to form an
intermediate image can be used. In addition, what is called a
line-head type ink jet recording head in which ink ejection
orifices are arranged in a linear manner substantially orthogonal
to the moving direction of a transfer member (i.e., substantially
parallel with the axis direction for a drum-shaped transfer member)
can also be used.
[0146] <Ink>
[0147] Each component for preparing an ink will be described
below.
[0148] [Coloring Material and Dispersion Thereof]
[0149] The ink for forming an intermediate image can be prepared by
using at least a coloring material, a resin (second resin) and a
liquid medium. As the coloring material, at least one of dyes,
carbon black and pigments such as organic pigments usable as the
coloring material in an ink can be used. The coloring material can
be contained in an ink in a dissolved and/or dispersed state in a
liquid medium. Specifically, various pigments, which are
characterized by achieving durability and quality of printed
matters, are preferred.
[0150] Examples of the pigment include known self-dispersion type
pigments and dispersant-dispersion type pigments, including
inorganic pigments and organic pigments, and these pigments can be
used singly or in combination of two or more of them. For such a
pigment, a dispersant is used as needed to stably disperse the
pigment in an ink. As the dispersant for an aqueous ink, a
dispersant such as a water-soluble resin having both a hydrophilic
moiety and a hydrophobic moiety in the molecular structure thereof
is specifically preferably used.
[0151] The content of the pigment in the ink is preferably 0.5% by
mass or more to 15.0% by mass or less and more preferably 1.0% by
mass or more to 10.0% by mass or less relative to the total mass of
the ink.
[0152] (Water and Water-Soluble Organic Solvent)
[0153] The ink can contain, as a solvent, water or an aqueous
liquid medium such as a mixture of water and a water-soluble
organic solvent. The water is preferably a deionized water prepared
by ion exchanging, for example. In the ink, the content of the
water is preferably 30% by mass or more to 97% by mass or less
relative to the total mass of the ink and is more preferably 50% by
mass or more to 95% by mass or less relative to the total mass of
the ink.
[0154] As the aqueous ink containing at least water as a liquid
medium, an aqueous pigment ink containing at least a pigment as the
coloring material can be used. The water-soluble organic solvent to
be used is not limited to particular types and any known organic
solvent can be used. Specific examples include glycerol, diethylene
glycol, polyethylene glycol, polypropylene glycol, ethylene glycol,
propylene glycol, butylene glycol, triethylene glycol,
thiodiglycol, hexylene glycol, ethylene glycol monomethyl ether,
diethylene glycol monomethyl ether, 2-pyrrolidone, ethanol and
methanol. Needless to say, two or more solvents selected from these
solvents can be used as a mixture. The content of the water-soluble
organic solvent in the ink is preferably 3% by mass or more to 70%
by mass or less relative to the total mass of the ink.
[0155] [Resin]
[0156] The ink contains a second resin as the resin for forming an
ink layer. The second resin is heated in the heating step to form a
coating film as an ink layer. The second resin is not limited to
particular types, and substantially the same resins previously
exemplified as the glossy layer-forming material (first resin) can
be used. Specifically, the second resin is preferably an acrylic
resin or a urethane resin. The resin may be present in any state of
a dissolved state or a dispersed state. The second resin may have a
function of reacting with an ink viscosity-increasing component in
the reaction liquid to increase the viscosity by, for example,
aggregation of the ink or may have a function as a pigment
dispersant for dispersing a pigment in the ink.
[0157] The amount of the second resin can be selected from a range
of 1% by mass or more to 30% by mass or less relative to the total
mass of the ink.
[0158] The ink may contain, in addition to the pigment and the
second resin, an ink viscosity-increasing resin and/or various
particles in order to improve the image quality or fixability. As
the ink viscosity-increasing resin, a resin capable of achieving an
intended ink viscosity-increasing effect can be selected from the
resins previously exemplified as the glossy layer-forming material.
As the constituent materials of the particles, various materials
can be selected. To further improve the image quality or
fixability, a material can be specifically used within such a range
as not to affect the heating temperature or the transfer
temperature of an ink layer. When resin particles are used in
addition the above second resin and the ink viscosity-increasing
resin, the resin particles may also have a function of increasing
the viscosity of an ink by a reaction with a viscosity-increasing
component in the reaction liquid to cause aggregation or the like.
The second resin preferably has a glass transition temperature of
30.degree. C. or more to 70.degree. C. or less and more preferably
40.degree. C. or more to 60.degree. C. or less.
[0159] [Other Additives]
[0160] Examples of the additional additives contained in the ink
include various additives such as various solvents, a surfactant, a
pH adjuster, an anticorrosive, an antiseptic agent, an antifungal
agent, an antioxidant, a reduction inhibitor, a water-soluble resin
and a neutralizer therefor and a viscosity modifier. These
additives can be contained as needed and can be used singly or in
combination of two or more of them.
[0161] <Heating Device for Resin Material Layer for Forming
Glossy Layer and Ink Layer>
[0162] A heating device for heating the resin material layer for
forming a glossy layer and the ink layer included in an
intermediate image formed on the transfer member (i.e., a heating
device for heating an intermediate image) is provided. Heating with
the heating device is performed in order to form an intermediate
image including a glossy layer as a coating film and an ink layer
as a coating film by using a first resin contained in the resin
material layer and a second resin contained in the ink layer. The
heating device may be any device capable of performing an intended
heat treatment. For example, a heating device of directly heating a
laminated body of the resin material layer and the ink layer or a
heating device of indirectly heating a laminated body of the resin
material layer and the ink layer through a transfer member.
Combination use of both the heating systems is more preferred.
Specific examples of the heating means include a hot air blower
such as a fan heater, a hot air dryer, an infrared heating device,
a flash fixing device and a heat generating device such as a
halogen heater. The support of a transfer member can be made from a
material including a metal capable of performing induction heating,
and a heating means of using the electromagnetic induction heating
can be used.
[0163] The heating device may be used in the above removal (drying)
treatment of the liquid in an ink. The heating device preferably
has a structure capable of changing the heating temperature in
accordance with melting or softening temperature characteristics of
a resin contained in the resin material layer.
[0164] <Temperature Controlling Unit>
[0165] A conveyance region of the image formation surface on the
transfer member between the heating device for forming coating
films of a resin material layer and an ink layer and the transfer
unit may be used as a temperature controlling unit to control the
temperature of an intermediate image. This process is also called a
temperature control step. The temperature control of the
intermediate image can be performed by natural heat radiation
(natural air cooling) or cooling using a cooling device. On the
basis of the conveyance speed of an image formation surface and the
temperature decrease history (pattern) of an intermediate image,
the distance between the heating device and the transfer unit is
set so as to enable an intended temperature control. The cooling
device may be any known device.
[0166] <Transfer Unit>
[0167] To transfer an intermediate image including a glossy layer
formed on the transfer member to a recording medium, the method for
bringing the recording medium into contact with the transfer member
or the device therefor may be any method or device capable of
performing an intended transfer step. Examples of the transfer unit
include a transfer unit having a transfer roller. The transfer unit
may have a system of simply performing pressure contact of a
recording medium with an intermediate image on a stretched transfer
member by using a transfer roller or a system of overlapping an
intermediate image on a transfer member with a recording medium and
inserting them into a nip between a transfer roller and a facing
support member.
[0168] The transfer unit may include a heating means. For a
transfer unit having a transfer roller, a heating device such as a
heater is preferably provided in the transfer roller to control the
temperature of an ink layer at the time of transfer. This is based
on the idea that the glossy layer is not melted or softened at the
time of transfer and is required to be a solid coating film but the
ink layer as a coating film is required to maintain a softened
state for expressing adhesiveness to a recording medium. In other
words, when the temperature of an ink layer is greatly decreased to
fail to satisfy the requirements, a heating device for transfer can
be used in order to soften the ink layer again. The heater may be
provided not only in a part in the transfer roller but also over
the peripheral surface of the transfer roller (surface to come into
contact with a recording medium).
[0169] The relation between the heating manner of a glossy layer
and transfer operations will be described with reference to FIG.
2.
[0170] As described above, an intermediate image 9 including a
laminated body of a resin material layer for forming a glossy layer
and an ink layer applied to the image formation surface of the
transfer member 1 is continuously heated by a hot air dryer 5 for
removing water and subsequently by a heater 6. By the heating, the
temperature of the laminated body of the resin material layer and
the ink layer included in the intermediate image on the transfer
member 1 is increased as the transfer member 1 is conveyed. The
condition change with time is shown in FIG. 2 as a temperature
change with time. The figure shows the temperature change when the
first resin for forming a glossy layer is a resin emulsion
containing resin particles having a minimum film forming
temperature of 85.degree. C. and the second resin contained in the
ink layer is a resin having a glass transition temperature of
60.degree. C. In FIG. 2, the vertical axis represents "temperature
of glossy layer", but the vertical axis indicating temperatures
less than the minimum film forming temperature (85.degree. C.)
represents the temperature of the resin material layer. The
"temperature of glossy layer" is substantially the same as the
temperature of the intermediate image.
[0171] When an intermediate image including a resin material layer
and an ink layer is formed on the transfer member 1 and is conveyed
through a heating region by a hot air dryer 5 and a heater 6, the
temperature of a first resin contained in the resin material layer
is increased. In the process, a second resin contained in the ink
starts to aggregate and soften. The temperature of the first resin
contained in the resin material layer is exceeding 85.degree. C.,
which is the minimum film forming temperature of the first resin
(minimum coat forming temperature of the first resin). On this
account, the resin particles as the first resin start to soften and
are likely to flow to fit to the image formation surface of the
transfer member 1 and concurrently the resin particles are fused to
each other, forming a coating film as a glossy layer. After that,
the intermediate image has passed through the heater 6, and the
heating is completed. The temperature of the glossy layer is then
gradually decreased and becomes lower than the minimum film forming
temperature of the first resin (minimum coat forming temperature of
the first resin) contained in the glossy layer. Before the
temperature becomes lower than the glass transition temperature of
the second resin in the ink layer, the intermediate image is
conveyed to a transfer operation. In the transfer operation, the
adhesiveness by the softening of the ink layer functions to
transfer the image including the ink layer and the glossy layer to
a recording medium 8. In the transfer, the glossy layer is in a
continuous coating film state and thus is readily released from the
image formation surface of the transfer member 1.
[0172] According to the present invention, a transfer type ink jet
recording method and a transfer type ink jet recording apparatus
capable of improving the transferability of an image from a
transfer member to a recording medium and improving the glossiness
of an image formed on a recording medium can be provided.
EXAMPLES
[0173] The present invention will next be described specifically
with reference to examples.
Example 1
[0174] A reaction liquid, a glossy layer-forming material- (first
resin-) containing liquid and an ink were prepared as shown below.
The component amounts with "%" are based on mass unless otherwise
noted.
[0175] [Preparation of Reaction Liquid] [0176] Citric acid: 30.0%
[0177] Glycerol: 15.0% [0178] Nonionic surfactant: 1.0% [0179]
[trade name: Acetylenol E100 (manufactured by Kawaken Fine
Chemicals)] [0180] Water: remainder
[0181] [Preparation of Glossy Layer-Forming Material- (First
Resin-) Containing Liquid 1] [0182] Resin emulsion of
styrene-acrylic copolymer (20% preparation liquid) (first resin):
50.0% [0183] [trade name: SK-202 (manufactured by Saiden Chemical
Industry Co., Ltd.)] [0184] (average particle diameter: 180 nm;
weight average molecular weight: 100,000; minimum film forming
temperature: 85.degree. C.; glass transition temperature:
96.degree. C.) [0185] Glycerol: 5.0% [0186] Diethylene glycol: 7.0%
[0187] Nonionic surfactant: 0.5% [0188] [trade name: Acetylenol
E100 (manufactured by Kawaken Fine Chemicals)] [0189] Water:
remainder
[0190] [Preparation of Black Ink]
[0191] First, 10% of carbon black (trade name: Monarch 1100,
manufactured by Cabot Corporation), 15% of an aqueous solution of a
pigment dispersant (a styrene-ethyl acrylate-acrylic acid copolymer
(second resin): an acid value of 240, a weight average molecular
weight of 5000, a solid content of 20%; neutralized with potassium
hydroxide), and 75% of pure water were mixed. The mixture was
placed in a batch type vertical sand mill (manufactured by Aimex),
and 200% of 0.3-mm zirconia beads were placed. The mixture was
dispersed for 5 hours while cooled with water. The dispersion
liquid was subjected to a centrifuge separator to remove coarse
particles, giving a black pigment dispersion liquid having a
pigment concentration of 10%.
[0192] The pigment dispersion liquid was used to prepare an ink in
accordance with the following formulation. [0193] Pigment
dispersion liquid: 20.0% [0194] (glass transition temperature of
contained resin: 60.degree. C.) [0195] Glycerol: 10.0% [0196]
Ethylene glycol: 5.0% [0197] Nonionic surfactant: 0.5% [0198]
[trade name: Acetylenol E100 (manufactured by Kawaken Fine
Chemicals)] [0199] Water: remainder
[0200] [Preparation of Cyan Ink]
[0201] The same procedure as for the black ink was performed with
the exception that the coloring material was changed from the
carbon black to Pigment Blue 15, giving a cyan ink.
[0202] [Preparation of Magenta Ink]
[0203] The same procedure as for the black ink was performed with
the exception that the coloring material was changed from the
carbon black to Pigment Red 7, giving a magenta ink.
[0204] [Preparation of Yellow Ink]
[0205] The same procedure as for the black ink was performed with
the exception that the coloring material was changed from the
carbon black to Pigment Yellow 74, giving a yellow ink.
[0206] [Recording Medium]
[0207] The following recording paper was used as the recording
medium. Aurora Coat, a basis weight of 186.1 g/m.sup.2
(manufactured by NIPPON PAPER INDUSTRIES CO., LTD.)
[0208] [Image Recording]
[0209] The above reaction liquid, the glossy layer-forming
material- (first resin-) containing liquid and the inks were set in
the transfer type ink jet recording apparatus in FIG. 1, and an
image was formed on the above recording medium. The transfer member
1 used here had a surface roughness Ra of 0.06 .mu.m. The surface
roughness Ra was determined with Vertscan 4.0 manufactured by
Mitsubishi Chemical Systems, Inc. Onto the transfer member 1,
first, the reaction liquid 31 was applied with a 200-line anilox
roller 34 in a reaction liquid coating device 3. The application
amount of the reaction liquid 31 was 1 g/m.sup.2 that was a
required amount to cause the pigment dispersion in the ink to
aggregate.
[0210] Subsequently, to the image formation surface of the transfer
member 1 applied with the reaction liquid 31, the glossy
layer-forming material-containing liquid 1 was ejected from an ink
jet recording head 41 and applied over the full-width of the image
formation surface of the transfer member 1. Subsequently, the black
ink, the cyan ink, the magenta ink and the yellow ink were ejected
from ink jet recording heads 42, 43, 44, 45 in response to image
signals, forming an intermediate image including a resin material
layer and an ink layer.
[0211] The intermediate image was then dried by a hot air dryer 5.
While the intermediate image passed through a drying region by the
hot air dryer 5, the intermediate image was dried by hot air at
75.degree. C. for 5 seconds, and the water in the intermediate
image was thoroughly removed.
[0212] After the drying, the intermediate image was heated by a
heater 6 integrated in a support roller 22. The heater was set to
give a surface temperature of 110.degree. C., and the temperature
of the image formation surface of the transfer member in contact
therewith was also increased to 110.degree. C. Accordingly, the
intermediate image can be heated. While the intermediate image
passed through the heating region, the intermediate image was
heated at 110.degree. C. for 3 seconds. The temperature of the
intermediate image in the heating step was determined by using an
infrared thermometer (not shown). During the process, the
temperature of the resin material layer changed in a similar
pattern to that in FIG. 2 and reached the minimum film forming
temperature, 85.degree. C., or higher while the back surface of the
image formation surface of the transfer member 1 with the
intermediate image was in contact with the support roller 22. As a
result, the resin particles contained in the resin material layer
formed a coating film while fitting to the image formation surface
of the transfer member, giving a glossy layer.
[0213] Next, the heating of the image formation surface of the
transfer member 1 with the intermediate image by the heater 6 was
turned off, and the intermediate image was conveyed to the position
of a transfer roller 71. During this conveyance, heating was not
performed but heat radiation was performed. Accordingly, the
temperatures of the transfer member and the intermediate image
including the glossy layer and the ink layer were gradually
decreased. When the intermediate image reached the position of the
transfer roller 71, the temperature of the glossy layer reached
70.degree. C. that was not higher than the glass transition
temperature of the resin contained in the glossy layer. The resin
in the ink had a glass transition temperature of 60.degree. C., and
thus the glossy layer was in the solid state, but the ink layer
maintained a softened state at this point. In this condition, the
transfer roller 71 applied a linear pressure of 600 N while
following the conveyance of the intermediate image on the transfer
member 1, and the intermediate image was pressed against a
recording medium and transferred, forming an image on the recording
medium. The temperature of the intermediate image in the transfer
step was regarded as substantially the same as the surface
temperature of the transfer member immediately after transfer, and
the surface temperature of the transfer member immediately after
transfer was determined with an infrared thermometer (not shown) as
the temperature of the intermediate image.
[0214] When the image transferred onto the recording medium was
visually observed, the image was satisfactory transferred onto the
recording medium 8, and the formed image had a high glossiness.
Comparative Example 1
[0215] The same procedure as in Example 1 was performed with the
exception that the resin emulsion of a styrene-acrylic copolymer
contained in the glossy layer-forming material- (first resin-)
containing liquid 1 was changed to the following resin emulsion of
an acrylic copolymer to prepare a liquid 2, forming an image on a
recording medium. [0216] Resin emulsion of acrylic copolymer (20%
preparation liquid) [0217] [trade name: ACF-15 (manufactured by
Saiden Chemical Industry Co., Ltd.)] [0218] (average particle
diameter: 200 nm; minimum film forming temperature: 40.degree. C.;
glass transition temperature: 60.degree. C.)
[0219] When the image transferred onto the recording medium was
visually observed, the image was satisfactory transferred onto the
recording medium 8, but the formed image had a lower glossiness
than the image in Example 1.
Example 2
[0220] The glossy layer-forming material- (first resin-) containing
liquid 1 was changed to the following liquid 3, and the reaction
liquid and the inks were set in the transfer type ink jet recording
apparatus in FIG. 1 in the same manner as in Example 1.
[0221] [Preparation of Glossy Layer-Forming Material- (First
Resin-) Containing Liquid 3] [0222] Resin emulsion of
styrene-acrylic copolymer (20% preparation liquid): 30.0% [0223]
[trade name: KE-1062 (manufactured by Seiko PMC)] [0224] (average
particle diameter: 80 nm; weight average molecular weight: 100,000;
minimum film forming temperature: 55.degree. C.; glass transition
temperature: 96.degree. C.) [0225] Paraffin wax emulsion: 20.0%
[0226] [trade name: AQUACER497 (manufactured by BYK Japan KK)]
[0227] (melting point: 60.degree. C.) [0228] Glycerol: 5.0% [0229]
Diethylene glycol: 7.0% [0230] Nonionic surfactant: 0.5% [0231]
[trade name: Acetylenol E100 (manufactured by Kawaken Fine
Chemicals Co., Ltd.)] [0232] Water: remainder
[0233] In the example, the minimum film forming temperature of the
glossy layer-forming material-containing liquid 3 was lower than
the minimum film forming temperature of the glossy layer-forming
material-containing liquid 1 used in Example 1, and thus the
heating temperature of the intermediate image by the heater 6 was
set at 100.degree. C.
[0234] In the conditions, a series of transfer image forming
operations were performed. The glossy layer-forming material
contains wax, and thus the releasability of the glossy layer and
the ink layer was further improved at the time of transfer.
Accordingly, a coating film having an extremely high smoothness was
able to be formed on the surface of the transferred image, and a
highly glossy image was able to be produced.
Example 3
[0235] As shown in FIG. 3, a noncontact type temperature sensor
(infrared thermometer) 10 for measuring the temperature of a glossy
layer was provided in a section from turning-off of the contact of
a heater 6 for heating to a transfer roller 71. The glossy layer is
present between the image formation surface of the transfer member
1 and the ink layer, but the ink layer has an extremely small
thickness of several to several tens of micrometers. Hence, the
temperature of the ink layer on the outermost surface of the
intermediate image measured by the noncontact type temperature
sensor 10 can be regarded as the temperature of the glossy
layer.
[0236] The temperature sensor 10 is provided in order to ascertain
the temperature of the resin contained in a glossy layer at the
time of transfer. In other words, the sensor is provided in order
to ascertain that the temperature is within an appropriate
temperature range of lower than the glass transition temperature of
the first resin contained in a glossy layer and not lower than the
glass transition temperature of the second resin contained in an
ink layer at the time of transfer. Hence, the temperature sensor 10
is most preferably provided in the transfer unit in terms of direct
measurement, but in such a case, the transfer conditions cannot be
controlled after the measurement. The temperature sensor 10 is thus
provided before the transfer unit.
[0237] By information on the temperature measured by the
temperature sensor 10 and the position of the temperature sensor
10, the transfer temperature of the glossy layer reaching the
transfer roller 71 can be forecast. When the measured temperature
of a glossy layer is out of an appropriate range, the operation of
the transfer type ink jet recording apparatus is controlled.
[0238] When the temperature of a glossy layer is higher than an
appropriate range at the time of transfer, the temperature is
required to be decreased, and the following method can be performed
to decrease the temperature, for example. In other words, in an
example method, the conveyance speed of the transfer member 1 is
decreased to increase the time until the execution of transfer, and
the temperature of the glossy layer is intended to be decreased
with the time. In the example, when the temperature measured by the
temperature sensor 10 is 10.degree. C. higher than the upper limit
temperature of an appropriate range, the rotation speed of the
support rollers 21 and 22 are decreased by 20% to increase the time
for decreasing the temperature of the glossy layer. This control
can be performed by changing the driving signal in a driving
controller (not shown) for the support rollers 21 and 22. If
another image is simultaneously formed by the ink jet recording
head group 4, a driving control system for the ink jet recording
heads and the operation setting of the hot air dryer 5 and the
heater 6 are also controlled in an interlocking manner.
[0239] Other methods for decreasing the temperature of a glossy
layer include a method of bringing a metal plate having a high
thermal conductivity into contact with the inner peripheral surface
of an endless belt included in the transfer member 1 in a section
to a transfer roller 71 to decrease the temperature of a glossy
layer and a method of sending air by a fan or the like to decrease
the temperature, for example.
[0240] When the temperature of a glossy layer is lower than an
appropriate range at the time of transfer, the temperature is
required to be increased, and a counter operation to the above
method can be performed to increase the temperature. In other
words, a method of increasing the conveyance speed, a method of
bringing a heating member having a large heat capacity into contact
with the inner peripheral surface of an endless belt or a method of
sending warm air can be performed, for example. By control during
the conveying operation of the transfer member 1 to adjust the
temperature of a coating film for gloss within an appropriate range
at the time of transfer, images having an appropriate gloss quality
can be output constantly.
Example 4
[0241] Some output images may not need high glossiness. In such a
case, the ink jet recording head 41 for applying a glossy
layer-forming material-containing liquid is suspended in the
transfer type ink jet recording apparatus in FIG. 1. By the
suspension operation, the application of a glossy layer-forming
material-containing liquid is temporarily stopped. In other words,
the application of a glossy layer-forming material-containing
liquid is not executed, and the intermediate image formation and
the following operation are performed. The control of "execution"
or "non-execution" of the driving of the ink jet recording head 41
can be performed by signal control in a driving controller (not
shown) of the ink jet recording head.
[0242] By selecting the application of a glossy layer-forming
material-containing liquid as above as needed, the degree of gloss
of an output image can be changed.
[0243] In response to signals for forming an intermediate image by
the ink jet recording heads 42 to 45, the ejection area of a glossy
layer-forming material-containing liquid by the ink jet recording
head 41 can be partly changed. By this system, only a part of an
output image can have high gloss.
Example 5
[0244] To execute the transfer step, the temperature of the glossy
layer formed by heating with the heating device 6 is required to be
lower than the glass transition temperature of the resin contained
in the glossy layer. Concurrently, the temperature is required to
be equal to or higher than the glass transition temperature of the
thermoplastic resin contained in the ink layer. However, depending
on the whole structure of an apparatus, a sufficient distance for
cooling to a temperature lower than the glass transition
temperature cannot be designed from a heating device to a transfer
roller in some cases. In such a case, a cooling device 11 is
effectively provided in a section from a heating device to a
transfer roller as shown in FIG. 4.
[0245] With the structure, based on the measurement result of a
temperature sensor 10, the temperature of an intermediate image
that reaches the transfer roller 71 can be forecast from the
relation to the temperature of the heating device. When the
temperature is not forecast to be lower than the glass transition
temperature at the position of the transfer roller 71, the cooling
device 11 is activated to decrease the temperature of a glossy
layer. This enables control of transfer in appropriate temperature
conditions.
Example 6
[0246] In FIG. 5, a transfer roller 71 is placed to face a transfer
member support roller 21, and the rollers are driven in an
interlocking manner. In other words, the transfer member support
roller 21 also serves as a rear support roller at the time of
transfer.
[0247] This structure can save component members, can increase the
space in the apparatus, and can increase the time for decreasing
the temperature of a glossy layer to a temperature lower than the
glass transition temperature of a first resin.
Example 7
[0248] FIG. 6 shows an embodiment of a transfer type ink jet
recording apparatus in which a sheet-shaped transfer member is
rotatable.
[0249] The apparatus shown in FIG. 6 has a sheet-shaped transfer
member 101 on the outer peripheral surface of a cylindrical-shaped
support 201, and as the support 201 rotates in the arrow direction,
an image formation surface of the transfer member 101 is conveyed.
Each device arranged around the transfer member 101 works in such a
way as to be synchronized with the conveyance of the image
formation surface, and the formation of an intermediate image and
the transfer of the image to a recording medium are performed.
[0250] The transfer member 101 is sequentially conveyed to
installation regions of a reaction liquid coating device 300 and an
ink jet recording head group 400 including an ink jet recording
head 401 for applying a glossy layer-forming material-containing
liquid and ink jet recording heads 402 to 405 for forming an
intermediate image. The reaction liquid coating device 300 has a
storage container 302 storing the reaction liquid, a fountain
roller 303, an anilox roller 304, and a doctor blade 305. The
reaction liquid is applied to the transfer member 101 by performing
the operation of the reaction liquid coating device 300 similar to
that of the reaction liquid coating device 3 in FIG. 1. By these
ink jet recording heads 401 to 405, an intermediate image 901
including a laminated body of a resin material layer and an ink
layer is formed. Next, the intermediate image 901 is sequentially
conveyed to installation regions of a hot air dryer 501, a heater
601 and a transfer roller 701 to form a highly glossy, transferred
image on a recording medium 801. A cleaning unit 112 may be
provided as needed.
[0251] The operation of each device for forming an image by the
apparatus is the same as that of each device described in FIG. 1
with the exception that the transfer member 101 is provided on the
outer peripheral surface of the support 201 and is conveyed as the
support 201 rotates.
[0252] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
* * * * *