Record receiver having plural interactive leaves or a colorless – Having a colorless color-former – developer therefor – or... – Spatial relationship specified between color-former and...
Reexamination Certificate
2000-06-16
2002-10-15
Hess, Bruce H. (Department: 1774)
Record receiver having plural interactive leaves or a colorless
Having a colorless color-former, developer therefor, or...
Spatial relationship specified between color-former and...
C427S152000, C503S200000
Reexamination Certificate
active
06465392
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material including a heat-sensitive recording layer and a protective layer provided on a substrate. The recording material has excellent scratch resistance and causes no sticking and residue adhesion at a heat-sensitive recording head or the like because the protective layer has excellent transparency, gloss, heat resistance and light resistance, and has excellent friction resistance and lubricity with respect to the heat-sensitive recording head.
2. Description of the Related Art
Recently, there has been development of heat-sensitive recording, because recording devices for heat-sensitive recording are simple, have high reliability and need no maintenance. Conventionally materials that utilize a reaction of an electron donative colorless dye with an electron receptive compound, materials that utilize a reaction of a diazonium salt compound with a coupler, and the like are widely known as heat-sensitive recording materials for heat-sensitive recording.
Recently, studies on improvement of properties of heat-sensitive recording materials, such as (1) color development density and color development sensitivity and (2) durability and the like of color image forming materials, have been conducted intensively. However, heat-sensitive recording materials have a drawback in that when exposed to sunlight for a long time or displayed in an office or the like for a long period of time, backgrounds become colored and image portions change color or discolor because of the light. Various methods have been suggested for ameliorating coloring of backgrounds and color changing or discoloration of image portions, but satisfactory results have not been consistently achieved.
On the other hand, there is growing demand for heat-sensitive recording systems in various fields such as facsimiles, printers, labels and the like. Accordingly, heat-sensitive recording materials with greater capabilities are required. For example, when a heat-sensitive recording material is heated image wise by a heat-sensitive recording head to record images, in order to obtain smooth prints without image forming failures and good images having excellent gloss, it is necessary for dynamic friction with the heat-sensitive recording head to be reduced to a certain value or less.
Particularly, in the case of a full color heat-sensitive recording material, when sufficient heat from a thermal head is intended to be imparted to layers near a substrate, heat of a relatively high energy level is applied to a surface protective layer, and the surface tends to roughen and manifest remarkably reduced gloss.
Therefore, waxes (for example, zinc stearate and the like) and matting agents, pigments and the like have been conventionally used for imparting friction resistance and lubricity to heat-sensitive recording materials. However, such means do not provide sufficient improvements in friction resistance and lubricity, and have drawbacks in that if the heat-sensitive recording material is a reflective material, reductions in transparency and gloss thereof (and if the heat-sensitive recording material is a transparent material, an increase in degree of haze thereof) result, and further, components thereof fuse to heat-sensitive recording heads, image-formed surfaces and the like, leading to faults such as adherence of residues, gloss unevenness and the like.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a heat-sensitive recording material which has excellent head properties, specifically, excellent friction resistance with respect to a heat-sensitive recording head and excellent lubricity, no adherence of residues to the heat-sensitive recording head, and improved travelling property and scratch resistance, while maintaining gloss of the heat-sensitive recording material.
The inventors of the present invention have intensively studied how to attain the above-described object, found that the object can be attained if a surface of the heat-sensitive recording material after image forming has a particular surface roughness, and completed the invention. Namely, the above-described object of the present invention is achieved by providing heat-sensitive recording materials having the following characteristics (a) to (g).
(a) In a heat-sensitive recording material including a heat-sensitive recording layer and a protective layer provided on a substrate, wherein when image is formed on said heat-sensitive recording material by an application energy of 120 mJ/m
2
, a surface roughness (Ra value) of an image-formed surface of the heat-sensitive recording material after image forming is at most 0.7 &mgr;m. The heat-sensitive recording material having the surface roughness of the image-formed surface as described above has excellent friction resistance with respect to a heat-sensitive recording head and excellent lubricity, causes no adherence of residues to the heat-sensitive recording head, and has improved travelling property and scratch resistance (head properties), while maintaining gloss.
(b) In the heat-sensitive recording material of (a), the surface roughness (Ra) of the heat-sensitive recording material before image forming is at most 1.0 &mgr;m or less.
(c) In the heat-sensitive recording material of (a) or (b), wherein a glossiness of the image-formed surface after image forming is at least 40% in terms of glossiness as defined in JIS Z-8741 (20 degrees).
(d) In a heat-sensitive recording material including a heat-sensitive recording layer and a protective layer provided on a substrate, the protective layer includes at least a long-chain alkyl ether-denatured polyvinyl alcohol, waxes, and inorganic ultra fine particles having an average primary particle size of at most 0.1 &mgr;m. When the protective layer is formed of components as described above, a heat-sensitive recording material having the above-described characteristic (surface roughness after image forming) of (a) can be provided efficiently. Consequently, a good balance of the above-described gloss and heat-related properties can be attained.
(e) The above-described long-chain alkyl ether-denatured polyvinyl alcohol having the above-described characteristic of (d) is an alkyl ether-denatured polyvinyl alcohol having 8 to 20 carbon atoms.
(f) The above-described long-chain alkyl ether-denatured polyvinyl alcohol is a polymer represented by a general formula (A) as follows:
(wherein, R
1
represents a hydrogen atom, a methyl group or —CH
2
CO
2
M; R
2
represents a hydrogen atom or —CO
2
M; R
3
represents a hydrogen atom, —CO
2
M, an amino group, an amide group, a substitutional amide group, a hydroxy group, a glycidyl group, a sulfonate group, a polyethylene oxide group, a polypropylene oxide group or a group carrying at least one of above-listed functional groups; R
4
represents a hydrogen atom or a methyl group; and R
5
represents an alkyl group having 8 to 20 carbon atoms, M represents a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, a sodium atom, a potassium atom or a lithium atom. n, x, y and z each represent a degree of polymerization).
(g) The above-described protective layer is formed by using a least a long-chain alkyl ether-denatured polyvinyl alcohol and other aqueous binder.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A heat-sensitive recording material of the present invention has a characteristic, as described above, that when image forming is conducted with an application energy of 120 mJ/m
2
, a surface roughness (Ra) of the image-formed surface of the heat-sensitive recording material after image forming is 0.7 &mgr;m or less. Namely, the present invention is based on the finding that when a surface roughness of a heat-sensitive recording material after image forming has a certain value or less, head properties such as scratch resistance, travelling property, resistance to adherence of residues to a thermal head, and the like can be im
Fuji Photo Film Co. , Ltd.
Hess Bruce H.
Sughrue & Mion, PLLC
LandOfFree
Heat-sensitive recording material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Heat-sensitive recording material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Heat-sensitive recording material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2954124