Heat-sensitive transferring recording medium

A heat-sensitive transferring recording medium comprises a base film, a heat melting ink layer provided on the under surface of the base film and a conveyance improving layer composed of a material selected from fatty acids, fatty acid derivatives, fatty alcohols, alkali metal salts of mono- or di-alkyl phosphoric acid esters of 8-18 carbon atoms, polyester copolymers, and other phosphoric acid esters.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a heat-sensitive transferring recording medium. 
2. Description of the Prior Art 
Heretofore, the conveyance property of heat-sensitive transferring 
recording media used in printers has been so poor that a part of a base 
film melts and sticks to a thermal head. Therefore, in order to improve 
the conveyance property, there have been used thermally crosslinking 
resins and thermosetting resins such as silicone resins, melamine resins 
and the like for a heat-sensitive member or a heat-sensitive transferring 
recording medium. However, these methods involve chemical reactions which 
complicate the procedures and require much labor. Furthermore, curling of 
the recording medium is easily caused. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a heat-sensitive 
transferring recording medium free from the above-mentioned drawbacks. 
Another object of the present invention is to provide a heat-sensitive 
transferring recording medium which does not stick to the thermal head of 
a printer, whose conveyance improving layer can be simply and easily 
formed, and which is free from curling. 
According to the present invention, there is provided a heat-sensitive 
transferring recording medium which comprises a base film, a heat melting 
ink layer provided on the undersurface of the base film, and a conveyance 
improving layer provided on the upper surface of the base film, said 
conveyance improving layer comprising a member selected from the group 
consisting of 
(1) fatty acids, 
(2) fatty acid derivatives, 
(3) fatty alcohols, 
(4) alkali metal salts of mono-or di-alkyl phosphoric acid esters having 
8-18 carbon atoms, 
(5) polyester copolymers having a molecular weight or 3000 or more prepared 
by polycondensation of (a) an aromatic dicarboxylic acid compound or an 
aliphatic dicarboxylic acid compound, (b) a diol having 2-4 carbon atoms, 
and (c) a polyethyleneglycol compound of a molecular weight of 2000 or 
more, 
(6) tri (polyoxyethylenealkyl or alkenyl ether) phosphoric acid esters of 
the formula, 
##STR1## 
where R is alkyl or alkenyl of C.sub.8 -C.sub.25, and l, m, and n are 
integers of 1-10, 
(7) phosphoric acid esters of the formula, 
##STR2## 
where R, m and n are as defined above and X is hydrogen or alkali metal, 
(8) phosphoric acid esters of the formula, 
##STR3## 
where R, n and X are as defined above, (9) phosphoric acid esters of the 
formula, 
##STR4## 
where R is as defined above, (10) phosphoric acid esters of the formula, 
##STR5## 
where R and X are as defined above, and (11) phosphoric acid esters of 
the formula, 
##STR6## 
where R and X are as defined above.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As the base film, there may be used various known films such as polyester 
film, polycarbonate film, triacetylcellulose film, nylon film, cellophane 
and the like. The thickness of the film is, for example, 2-30.mu.. 
Known heat melting ink layers may be used. For example, the heat melting 
ink layer may be produced by applying a mixture of a binder such as 
carnauba wax, beeswax and the like and a coloring agent to a base film by 
means of hot-melt coating, or by applying a liquid coating composed of a 
binder and a coloring agent dispersed in an appropriate solvent to a base 
film by means of solvent coating. 
In addition to known heat melting ink layer, there may be used a new heat 
melting ink layer. 
The new preferable heat melting ink layer is mainly composed of wax, a 
thermoplastic base polymer, an adhesivity imparting agent, and a coloring 
agent. 
A heat melting ink layer can be formed by dispersing the above-mentioned 
ingredients in a solvent and applying the resulting mixture to a base film 
according to a solvent coating method, or by heat-melting the ingredients 
and applying the molten mixture to a base film according to a hot melt 
coating method. 
As the wax, waxes having a melting point or softening point of 
60.degree.-110.degree. C. are preferable. Examples of the wax are Japan 
wax, beeswax, ceresine wax, spermaceti, microcrystalline wax and the like. 
As the thermoplastic base polymer, there may be used ethylene-vinyl acetate 
copolymers, polyamides, polyesters, synthetic rubber, ethylene-ethyl 
acrylate copolymer, atactic polypropylene, polyvinyl acetate and the like. 
As the adhesivity imparting agent, there may be used rosin, its 
derivatives, terpene resins, hydrocarbon resins, low molecular weight 
styrene resins, coumarone-indene resins, and the like. The adhesivity 
imparting agent imparts a wetting property and a hot tack to a receiving 
paper or sheet. 
As the coloring agent, there may be used various dyes or pigments 
ordinarily used in copying paper technology. 
If desired, a plasticizer may be added. 
Referring to the drawing, the heat-sensitive transferring recording medium 
comprises a base film 2, a heat melting ink layer 3 provided at the lower 
surface of the base film 2 and a conveyance improving layer 1 provided on 
the upper surface of the base film 2. 
Typical fatty acids used for the conveyance improving layer are, for 
example, fatty acids having 12 or more carbon atoms such as lauric acid, 
myristic acid, margaric acid, stearic acid, montanic acid and the like. 
As the fatty acid derivatives used for the conveyance improving layer, 
there may be mentioned metal salts of fatty acids and fatty acid esters. 
Typical metal salts of fatty acids are, for example, sodium, barium, 
lithium and silver salts of straight chain fatty acids of C.sub.8 
-C.sub.18 such as caprylic acid, lauric acid, myristic acid, palmitic 
acid, stearic acid and the like, copper and calcium salts of straight 
chain fatty acids of C.sub.8 -C.sub.10 such as caprylic acid, pelargonic 
acid, capric acid and the like, and aluminum mono-, di- or tristearate. 
Typical fatty acid esters are, for example, glyceryl 1-monostearate, 
glyceryl 1,3-distearate, glyceryl tristearate and the like. 
As fatty alcohols used for the conveyance improving layer, there may be 
mentioned lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl 
alcohol, oleyl alcohol and the like. 
The conveyance improving layer may be formed by, for example, dissolving 
the fatty acid, fatty acid derivative or fatty alcohol in an appropriate 
solvent such as methanol and applying the resulting solution to a base 
film, for example, in an amount of about 0.3-3 g/m.sup.2 (as solid matter) 
according to a solvent coating process. 
As the alkali metal salts of mono- or di-alkyl phosphoric acid esters 
having 8-18 carbon atoms used for the conveyance improving layer, there 
may be mentioned, for example, alkali metal salts such as lithium, sodium, 
potassium salts and the like of mono- or di-higher alkyl, or alkenyl 
esters such as lauryl, cetyl, stearyl, oleyl esters and the like of 
phosphoric acid. 
As the polyester copolymers having a molecular weight of 3000 or more 
prepared by polycondensation of (a) an aromatic dicarboxylic acid compound 
or an aliphatic dicarboxylic acid compound, (b) a diol having 2-4 carbon 
atoms, and (c) a polyethyleneglycol compound of a molecular weight of 2000 
or more, there may be used the following polyester copolymers. 
Typical aromatic dicarboxylic acid compounds are terephthalic acid, 
isophthalic acid, phthalic acid, 2,6-naphthalene-dicarboxylic acid and the 
like and esters thereof such as dialkyl esters of terephthalic acid and 
the like. 
Typical aliphatic acid compounds are sebacic acid and the like and esters 
thereof. 
Typical diols are ethylene glycol, diethylene glycol, propylene glycol, 
butane diol, and the like. 
Typical polyethylene glycol compounds of a molecular weight of 2000 or more 
are polyethylene glycol, monoethers of polyethylene glycol such as higher 
alcohol monoether, monophenyl ether of polyethylene glycol and the like, 
and monoesters of polyethylene glycol such as higher fatty acid monoesters 
or monophenyl esters of polyethylene glycol. 
The dicarboxylic acids may be used alone or in combination. For example, a 
dialkyl ester of terephthalic acid is used as a main component and a small 
amount of isophthalic acid, phthalic acid, 2,6-naphthalene-dicarboxylic 
acid, sebacic acid or ester thereof is added to the main component. 
Each of the aromatic dicarboxylic acid compound, the aliphatic dicarboxylic 
acid compound and the diol may be used alone or in combination, and one of 
them may be used alone while the other may be used in combination. 
The conveyance improving layer may be formed, for example, in an amount of 
0.1-5 g/m.sup.2 (as solid matter) by coating. 
As to the compound of (6), Formula (I) above, alkyl and alkenyl of the 
tri(polyoxyethylenealkyl or alkenyl ether) phosphoric acid esters have 
usually 8-25 carbon atoms, preferably 12-18 carbon atoms and are of 
straight chain or branched, and the addition mole number of ethylene 
oxide, i.e., l. m or n, is usually 1-10, preferably 1-6. 
Representative tri(polyoxyethylenealkyl or alkenyl ether) phosphoric acid 
esters are tri(polyoxyethylene) lauryl ether phosphoric acid esters (l, m, 
n=2), tri(polyoxyethylene)lauryl ether phosphoric acid esters (l, m, n=4), 
tri(polyoxyethylene)stearyl ether phosphoric acid esters (l, m, n=3), 
tri(polyoxyethylene) stearyl ether phosphoric acid esters (l, m, n=5), 
tri(polyoxyethylene)oleyl ether phosphoric acid esters (l, m, n=4), and 
the like. 
Representative phosphoric acid esters of (7), Formula (II), are potassium 
di(polyoxyethylene) cetyl ether phosphate (m, n=5), sodium 
di(polyoxyethylene)cetyl ether phosphate (m, n=5), sodium 
di(polyoxyethylene)lauryl ether phosphate (m, n=3), potassium 
di(polyoxyethylene)lauryl ether phosphate (m, n=3), and the like. 
Representative phosphoric acid esters of (8), Formula (III), are 
dipotassium mono(polyoxyethylene) lauryl ether phosphate (n=3), disodium 
mono(polyoxyethylene)lauryl ether phosphate (n=3), dipatassium 
mono(polyoxyethylene)cetyl ether phosphate (n=5), disodium 
mono(polyoxyethylene)cetyl ether phosphate (n=5) and the like. 
Representative phosphoric acid esters of (9), Formula (IV), are tristearyl 
phosphate, trilauryl phosphate, tricetyl phosphate and the like. 
Representative phosphoric acid esters of (10), Formula (V), are potassium 
distearyl phosphate, sodium dilauryl phosphate, potassium dicetyl 
phosphate and the like. 
Representative phosphoric acid esters of (11), Formula (VI), are 
dipotassium monostearyl phosphate, disodium monostearyl phosphate, 
dipotassium monolauryl phosphate, disodium monolauryl phosphate, 
dipotassium monocetyl phosphate and the like. 
The conveyance improving layer may be formed, for example, in an amount of 
0.1-5 g/m.sup.2 (as solid matter) by coating a compound of (6)-(11) as 
mentioned above. 
EXAMPLE 1 
A known heat melting ink was applied to the under surface of a polyester 
film of 3.mu. thick. To the upper surface of the polyester film was 
applied a coating composed of 1000 ml of a heated methanol and 25 g of 
sodium stearate in an amount of 0.5 g/m.sup.2 to form a conveyance 
improving layer. 
The resulting heat-sensitive transferring recording medium was subjected to 
a printing operation by using P6 printer (tradename, manufactured by Fuji 
Xerox Co., Japan). No sticking of the recording medium to the thermal 
head, was caused and the printing was smoothly effected. Furthermore no 
curling of the recording medium occurred and the recording medium was able 
to be easily loaded in a printing machine. 
When the conveyance improving layer was not formed, sticking of the 
recording medium to the thermal head was caused, and the resulting printed 
letters were not sharp. 
EXAMPLE 2 
The procedure of Example 1 was repeated except that a coating produced by 
mixing 2 parts by weight of aluminum distearate and 98 parts by weight of 
ethanol and heating to 50.degree. C. was used in place of the coating in 
Example 1. The coating amount was 1 g/m.sup.2. The resulting 
heat-sensitive transferring recording medium was subjected to a printing 
operation by using P6 printer (tradename, manufactured by Fuji Xerox Co., 
Japan). A good result as in Example 1 was obtained. 
EXAMPLE 3 
To the lower surface of a polyester film of 3.mu. thick was applied a 
mixture produced by mixing 30 parts by weight of carnauba wax, 35 parts by 
weight of ester wax, 25 parts by weight of a pigment and 10 parts by 
weight of an oil by using a heated roll mill to form a heat melting ink 
layer. Then, to the upper surface of the polyester film was applied a 3% 
aqueous solution of potassium lauryl phosphate (a mixture of monoester 
which diester) and dried to form a coating of about 0.2 g/m.sup.2. 
The resulting heat-sensitive transferring recording medium was subjected to 
printing by using P6 printer (tradename, manufactured by Fuji Xerox Co., 
Japan). The conveyance property was excellent. There was no sticking of 
the recording medium to the thermal head, and, printing was smoothly 
effected. In addition, the recording medium did not suffer from curling 
and was easily loaded in a printing machine. 
When the conveyance improving layer was not formed, the conveyance property 
was so poor that sticking of the recording medium to the thermal head 
occurred and the printed letters were not sharp. 
EXAMPLE 4 
Repeating the procedure of Example 3 except that a 2% emulsion of a 
polyester copolymer having a molecular weight of about 5000 prepared by 
condensation of 150 parts by weight of dimethyl terephthalate, 41 parts by 
weight of ethyleneglycol, and polyethyleneglycol monophenyl ether having a 
molecular weight of 3000 was used in place of potassium lauryl phosphate, 
there was obtained a conveyance improving layer 0.1 g/m.sup.2. 
Print testing was conducted following the procedure as in Example 3. The 
result was as good as that in Example 3. 
EXAMPLE 5 
To the lower surface of a polyester film of 3.mu. thick was applied a 
mixture produced by mixing 30 parts by weight of carnauba wax, 35 parts by 
weight of ester wax, 25 parts by weight of a pigment and 10 parts by 
weight of an oil by using a heated roll mill to form a heat melting ink 
layer. Then, to the upper surface of the polyester film was applied a 3% 
aqueous solution of a mixture of potassium di(polyoxyethylene) lauryl 
ether phosphate (m, n=3) and dipotassium mono(polyoxyethylene) lauryl 
ether phosphate (n=3) (weight ratio of 1:1) which dried to form a coating 
of about 0.2 g/m.sup.2. 
The resulting heat-sensitive transferring recording medium was subjected to 
printing by using P6 printer (tradename, manufactured by Fuji Xerox Co., 
Japan). The conveyance property was excellent. There was no sticking of 
the recording medium to the thermal head, and, printing was smoothly 
effected. In addition, the recording medium did not suffer from curling 
and was able to be easily loaded in a printing machine. 
When the conveyance improving layer was not formed, the conveyance property 
was so poor that sticking of the recording medium to the thermal head 
occurred and the printed letters were not sharp. 
EXAMPLE 6 
Repeating the procedure of Example 5 except that a 3% aqueous solution of 
tri(polyoxyethylene) stearyl ether phosphoric acid ester (l, m, n=5) was 
used in place of potassium polyoxyethylene lauryl ether phosphate, there 
was obtained a conveyance improving layer of 0.1 g/m.sup.2. 
Print testing was carried out following the procedure as in Example 5, and 
the result was as good as that in Example 5. 
EXAMPLE 7 
Repeating the procedure of Example 5 except that an equeous solution of 
tri(polyoxyetnylene) stearyl ether phosphoric acid (l, m, n=5), disodium 
monolauryl phosphate and sodium dilauryl phosphate (weight ratio of 1:1:1) 
was used in place of potassium polyoxyethylene lauryl ether phosphate, 
there was produced a conveyance improving layer of 0.1 g/m.sup.2. 
Print testing was effected following the procedure of Example 5 to obtain 
as good a result as in Example 5. 
EXAMPLE 8 
Repeating the procedure of Example 5 except that an aqueous solution of 
tri(polyoxyethylene) lauryl ether phosphoric acid ester (l, m, n=4) and 
trilauryl phosphate (weight ratio of 1:1) was used in place of the mixture 
of the potassium polyoxyethylene lauryl ether phosphates, there was 
obtained a conveyance improving layer of 0.1 g/m.sup.2. 
Print testing was carried out following the procedure as in Example 5, and 
the result was as good as that in Example 5. 
EXAMPLE 9 
The procedure of Example 1 was repeated except that a heat melting ink 
layer was formed by applying the following composition: 
______________________________________ 
Microcrystalline wax 
20 parts by weight 
Ethylene-vinyl acetate 
5 parts by weight 
copolymer 
("Everlite", tradename, 
supplied by Sumitomo 
Kagaku Kogyo K.K.) 
Low molecular weight 
10 parts by weight 
styrene resin 
("Himer ST-95" tradename 
supplied by Sanyo Kasei K.K.) 
Carbon black 20 parts by weight 
("MA-10", tradename, 
supplied by Mitsubishi 
Kasei K.K.) 
Toluene 45 parts by weight 
100 parts by weight 
______________________________________ 
to the base film, according to a solvent coating method, in the thickness 
of 4.mu.(as solid matter). 
The resulting heat-sensitive transferring recording medium was tested for 
the printing characteristics by using P6 printer (tradename, manufactured 
by Fuji Xerox Co., Japan). No sticking of the recording medium to the 
thermal head occured, and the printing was smoothly effected. No curling 
of the recording medium occured, and the recording medium was able to be 
easily loaded in a printing machine. In addition, the resolution was good 
and the transferring property was improved. 
EXAMPLE 10 
The procedure of Example 9 was repeated except that a heat melting ink 
layer was formed by applying the following composition: 
______________________________________ 
Carnauba wax 30 parts by weight 
Paraffin wax 20 parts by weight 
Wax oxide 15 parts by weight 
Ethylene-vinyl 5 parts by weight 
acetate copolymer 
Terpene resin 10 parts by weight 
Carbon black 20 parts by weight 
100 parts by weight 
______________________________________ 
The results were similar to those in Example 9.