FI56994B - BEKLAETT SYNTETISKTKT PAPPER SOM LAEMPAR SIG FOER OFFSETTRYCK - Google Patents

Description

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Patent- ocn registerityrelsen Anaökan utlafd och utl.skrlfMn puMicarad 31.01.80 (32) (33) (31) Requested «toikaus — Bagird priorities 18.06.73

Japan-Japan (JP) 678U9 (71) Kanzaki Paper Manufacturing Co., Ltd., 9 ~ 8 Yonchome, Ginza, Chou-ku,

Tokyo, Toray Industries, Inc., 2 Nichome, Muromachi, Nihonbashi,

Chou-ku, Tokyo, Japan-Japan (JP) (72) Seigoro Fujita, Hyogo, Tojiro Kitahori, Hyogo, Japan-Japan (JP) (7U) Antti Impola (5U) Coated synthetic paper suitable for transfer printing -Beklätt synthetics This invention relates to an improved coated synthetic paper and a method of making the same. In particular, the invention relates to a coated synthetic paper made of a synthetic pulp of a polyolefin, the surface layer of which is suitable for transfer printing.

The synthetic pulp of polyolefin is inexpensive and excellent in that it has good heat resistance, high strength in both dry and wet conditions, and good dimensional stability that can never be achieved with natural cellulosic pulps. Several attempts have been made to provide pigment-coated synthetic paper that would have taken advantage of these advantages of polyolefin synthetic pulp. For example, Japanese Application No. 29 * 607 of 1972 discloses a coated synthetic paper having a coating layer made of inorganic pigments, for example clay, calcium carbonate, glossy white, talc and the like, and binders such as casein, starch, butylene, styrene, styrene. on a base paper made exclusively of polyolefin synthetic pulp or of a mixture of this and natural cellulose pulp and / or other synthetic pulp. However, such a coated synthetic paper is disadvantageous in that the ink does not transfer properly, especially in a multicolor transfer printing. Generally, in a multicolor transfer printing, the source solution remains on the surface of the sheet during the printing process if the surface of the coated paper is poor in absorbent source solution. The presence of the source solution on the surface of the paper prevents the paper from receiving the ink that must be transferred from the pad cylinder to the surface of the paper. That is, when an aqueous coating composition substantially containing a pigment component and a binder component is applied to the surface of a polyolefin synthetic pulp base paper and the coated paper is then dried, the aforementioned coating composition penetrates the base paper more slowly in the event that the base paper is slower. Thus, the binder which binder in the coating composition moves towards the coated surface of the sheet in the drying process and the binder in the resulting coating layer is more densely distributed close to the surface. This is the reason why coated synthetic paper is not good in absorbing the source solution. Although the amount of polyolefin pulp used is relatively small, there is a lack of absorption of the source solution locally. If the amount of polyolefin pulp used is relatively large, the lack of absorption of the source solution occurs mainly over the entire surface of the paper.

On the other hand, in terms of convenience of handling and reduction of postage and shipping costs, it is desirable to reduce the weight of the pigmented coated paper. Reducing the thickness of the base paper for this purpose will result in a deterioration in the strength, brightness or whiteness of the paper and opacity. It is hardly possible to avoid the above disadvantages by using ordinary natural cellulose paper with a pigment coating.

The main object of the present invention is to provide an improved coated synthetic paper suitable for transfer weight.

Another object of the invention is to provide an improved coated synthetic paper having good opacity, good brightness or whiteness and good dimensional stability.

It is a further object of the invention to provide an improved coated synthetic paper which is relatively light but sufficiently rigid.

It is a further object of the invention to provide an improved method of making the above-mentioned coated synthetic paper.

Other objects and advantages of the invention will become more apparent from the following description of the invention.

The above-mentioned objects of the invention can be achieved by preparing a synthetic paper coating layer containing polyolefin made of a pigment component and a binder component, said pigment component being an organic polymer pigment in fine particles. More specifically, a coated synthetic paper suitable for transfer weight according to the invention is characterized in that it comprises a base paper sheet containing at least 5% by weight of a fibrous material made of polyolefin pulp and a coating layer formed on at least one surface of said base paper sheet and said is made mainly of a binder component and a pigment component and that at least a part of said pigment component is an organic polymer pigment in fine particles.

According to the invention, it has been found that the transfer printability of a synthetic paper made of polyolefin pulp is unexpected and considerably improved by forming a coating layer on the surface of the synthetic paper using a coating composition comprising fine particles of organic polymers. Thus, the polyolefin synthetic paper of the present invention is characterized in that it is coated with a coating composition containing certain organic polymer particles.

Suitably 5-95% by weight of the fibrous material of the base paper constitutes the polyolefin pulp. The remaining part of the fibrous material may be natural non-cellulosic pulp.

At least 5% by weight or more, preferably at least 10% by weight of the dry weight of the pigment component may be the organic polymer pigment in fine particles. The pigment component may be a mixture of finely divided organic polymer pigment and inorganic pigment.

The amount of the binder component in the coating layer may be 5 to 100 parts by weight, preferably 8 to 35 parts by weight per 100 parts by dry weight of the pigment component included in the coating layer.

Most preferably, the organic polymer pigment used according to the invention is made of finely divided particles of an organic polymer having a deflection temperature higher than 30 ° C, preferably higher than 50 ° C, determined according to ASTM standard D-648. Most preferably, the organic polymer pigment is formed by fine particles having an average size of 0.1 to 1.0 microns.

In a preferred embodiment of the invention, said organic polymer pigment is formed by finely divided members of a member selected from the group consisting of polystyrene, polymethyl methacrylate, and copolymers of the foregoing and another vinyl monomer.

The amount of the coating composition comprising the above-mentioned organic polymer pigment should be at least 0.5 g / m 2, preferably 5.0 to 50 g / m 2 dry weight.

The polyolefin pulp used according to the invention may be made of p ty of fibrils and has a specific surface area of at least 0.7 m / g. The polyolefin pulp may be made of a polyolefin polymer and a hydrophilic polymer.

The fibrous portion of the base sheet of coated synthetic paper of the invention is made of a polyolefin pulp containing a hydrophilic component. Polyolefins for polyolefin pulp include homopolymers obtained by polymerizing olefin monomers such as ethylene, propylene, 4-methylpentene-1, butene-1, styrene, and copolymers of olefins. Also included are copolymers obtained by polymerizing these olefins with copolymerizable vinyl monomers such as ethylene-vinyl acetate copolymer and ethylene-acrylic acid salt copolymer.

Examples of the hydrophilic component are polymers having a hydroxyl group, for example polyvinyl alcohol, a siphoned ethylene-vinyl acetate copolymer, a polyvinyl alcohol having a radically graft polymerized vinyl monomer with a polymer having a copolymer such as styrene or methyl methacrylate, such as styrene or methyl methacrylate; hutene tricarboxylic acid, maleic acid, itaconic acid and their partial esters, polymers having an amide group such as polyethylene oxide or carboxymethylcellulose.

These hydrophilic components can be incorporated into the polyolefins by polymer blending and / or graft polymerization. The weight ratio of hydrophilic component to polyolefin in the fibrous material is preferably in the range of 0: 100 to 40:60, most preferably 1:99 to 50:? A common heat-resistant agent, an antioxidant and an ultraviolet light absorbing agent can be added to the polyolefin blend to produce a polyolefin pulp. Inorganic powder such as silica, alumina, talc, calcium carbonate, calcium sulfite and calcium sulfate may also be added as a filler. The polyolefin fiber material can be obtained by utilizing emulsion spraying methods, spray spinning, solution cutting, uniaxial stretching and cleavage, melt spinning, etc. Of these methods, the emulsion spray-spinning method, the spray-spinning method, and the solution-cutting method are suitable.

The emulsion spray spinning technique is known per se from, for example, U.S. Pat. No. 3-808,091. According to this emulsion spray spinning method, the fibrous material for the pulp is prepared by mixing polyolefin, a polyolefin solvent and a non-solvent to form a mixture, heating the mixture with vigorous stirring to produce a heated emulsion in which the polyolefin is dissolved and spraying the heated emulsion under high pressure. Examples of polyolefins are polyethylene, hexane as solvent, sodium laurylbenzenesulfonate as surfactant and water containing polyvinyl alcohol as dispersion medium or water containing polyvinyl alcohol as solvent. The synthetic pulp obtained by decomposing the injected fibrous material has a high specific surface area and includes a hydrophilic polymer and a surfactant. The synthetic pulp thus obtained can be well suspended in water and has a good self-binding property.

In the spray spinning method, a polyolefin dissolved in an organic solvent is injected through a die at a high temperature and high pressure. In this method, the fibrous material can hardly contain a hydrophilic polymer, and thus it is necessary to carry out the treatment with the hydrophilic polymer and the surfactant in order to achieve decomposition into a fibrous material having hydrophilic properties. This spray spinning method is also known, for example, from U.S. Patent No. 3-081,519.

The solution cutting method is known per se from German patent publication 2,058,386 and British patent publication 868,651. For example, a polymer solution is added to a polymer non-solvent to separate the polymer, and the shear force is applied to the polymer that is separated to provide a fibrous material. It is also possible to produce a fibrous material by applying shear to a polymer e-rotated in the olefin polymerization step. The fibrous material thus obtained by the solution cutting method is then subjected to a step of imparting hydrophilic properties to it, as well as by spray-spinning techniques.

Certain hydrophilic components, such as polyvinyl alcohol, saponified ethylene-vinyl acetate copolymer, polyethylene oxide, polyacrylamide, and modified starch, can be added to a fibrous material obtained by self-disintegration by one of the above methods, so that it is easily dispersed

t 56994

In general, a polyolefin synthetic pulp has a complex microfiber fine structure or microfilm.

The specific surface area of the synthetic pulp may be greater than 2 2 0.7 m / g, preferably greater than 1.0 m / g, measured according to the BET method.

If the specific surface area of the synthetic pulp is less than 0.7 m / g, the above-mentioned objects of the invention cannot be achieved.

The polyolefin pulp thus prepared can be made into paper sheets alone or in combination with a cellulosic pulp on a conventional paper machine. At least 5% by weight of the fibrous material of the paper sheet should be polyolefin pulp. In the case where the weight of the polyolefin pulp in the sheet is less than 5%, the above-mentioned advantages due to the use of the polyolefin pulp cannot be obtained.

The most suitable sheet of paper is made of a mixture of polyolefin pulp and natural cellulose pulp, although it may be made of a mixture of polyolefin pulp and some other synthetic pulp. In the case where the paper sheet is made of a mixture of polyolefin pulp and natural cellulose pulp, the weight ratio of the mixture may suitably be in the range of 5:95 to 95: 5 ·

In the papermaking step, the usual fillers, adhesives and dyes can be added without losing the advantages achieved by the invention.

A useful coating composition of this invention is an aqueous composition containing substantially a pigment component and a binder component. At least a portion of the pigment component contains finely divided particles of an organic polymer.

The fine particles of the organic polymer are preferably spherical and / or spheroidal in shape, although they may also be in other shapes. The particle size can average 0.1 to 1.0 microns. It is a requirement that the particles cannot form a film in the application proportions when drying the coating composition or finishing the coated paper. Suitably the organic polymeric particles have a deflection temperature of at least 30 ° C, but most preferably at least 50 ° C as determined and measured according to ASTM Standard D-648.

These described particles can be prepared by emulsion polymerization of a suitable monomer, a mixture of such monomers, or by emulsifying a suitable polymer prepared by another method, for example, slurry or solution polymerization. Any conventional finishing technique can then be used to produce finely divided particles.

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Suitable organic materials for fines include polymonovinylidene aromatics such as polystyrene, poly (N-methylstyrene), poly (4-ethylstyrene), poly (1-vinylnaphthalene), etc. Polyolefins, polyalphaolefins such as polyvinyl (hexafluoropropylene), polyethylene, polypropylene, poly (1-butene), poly (4-methyl-1-pentene), polyvinylidene chloride, polyO, 2-difluoroethylene), oC, β-ethylenically unsaturated acids esters such as polymethacrylates, polychloroacrylates and polychloromethacrylates, etc. * poly (methyl methacrylate), poly (isopropyl chloroacrylate), poly (2-chloroethyl methacrylate), poly (cyclohexyl chloroacrylate), poly (cyclohexyl chloroacrylate), poly (methyl chloroacrylate) poly (e-thene 1,5-naphthalate), polyethylene terephthalate-poly (hexamethylene adipamide), polyethylene terephthalate, · poly (hexamethylene adipamide), poly (E-capramide), poly (decamethen dipamide), polycarbonate, polyacetal, polyvinyl formal, polyvinyl butyral, etc. Copolymers of the monomers constituting the above polymers, such as ethylene-vinyl acetate copolymer, ethylene-propado copolymer, etc. are also suitable.

Various other copolymerizable monomers, such as conjugated and diethylene-diethylenically unsaturated monomers, alkyl acrylates, and acrylonitrile, may be present in small amounts as a comonomer in the aforementioned suitable polymers. Typical examples of such conjugated diethylene unsaturated monomers are 1,3-butadiene, isoprene, 2-chloro-1,3'-butadiene and divinylbenzene. Typical examples of such alkyl acrylates are methyl acrylate, ethyl acrylate, n-propyl acrylate, sec-butyl acrylate and n-butyl acrylate. OC, β-ethylenic unsaturated carboxylic acids and their anhydrides such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid and maleic anhydride can also be used as copolymerizable components of suitable polymers. For example, copolymers such as ethylene-acrylic acid copolymer, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, etc. are also suitable polymers according to the present invention.

Among the above-mentioned organic polymers, vinyl polymers and vinyl copolymers are suitable for use in practicing this invention.

A coating composition useful in the present invention is an aqueous coating composition which may be prepared by dispersing the above organic polymer particles alone or in combination with suitable inorganic pigments in an aqueous solution containing a binder or by mixing an organic polymer emulsion and a binder in an aqueous solvent. Useful binders for said coating composition include natural binders and synthetic binders commonly used in the preparation of known aqueous pigment coating compositions. Examples are proteins such as casein, soybean protein, gelatin, etc. * starches or derivatives thereof such as dextrin, natural starch, oxidized starch, esterified starch, etherified starch, cationic starch, phosphatosylated starch, etc. loose, hydroxyethylcellulose, etc .; conjugated diene polymer latices such as styrene-butadiene copolymer, methyl methacrylate-Buta diene copolymer, etc .; acrylic polymer latexes, such as polymers or copolymers of acrylic esters and / or methacrylic esters, etc .; vinyl polymer latices such as ethylene vinyl acetate copolymer, etc .; polymer latexes modified with functional groups such as carboxyl group, etc .; synthetic resin binders such as polyvinyl alcohol, olefin-maleic anhydride copolymer, melamine resin, etc. The example binders can also be used as mixtures.

As the inorganic pigment that can be mixed with the fine particles of the organic polymer may be kaolin, clay, calcium carbonate, calcium silicate, calcium sulfate, calcium sulfite, titanium oxide, aluminum hydroxide, barium sulfate, zinc oxide, cetine white, talc, colloidal, talc, talc, talc, talc, talc, talc, a suitable mixing ratio of pigments is 100: 0 to 5:95 by solid weight. If the amount of inorganic mixed pigments exceeds said limit, the desired effects of the present invention cannot be achieved. Most preferably, the mixing ratio is 100: 0-10: 90 solid weight. Because different adhesives provide different adhesions, the amount used is not standardized. The amount of binder is usually 5 to 100 parts by weight, preferably 8 to 35 parts by weight per 100 parts by weight of pigments (including organic polymer particles). The coating composition thus obtained may, of course, contain additives such as dispersants, dissolution inhibitor, stabilizer, flow modifier, colorant, antifoam agent, etc. The above coating composition is applied as a base paper with coating equipment such as wing coater, air-knife coater, roll coater, brush coater, curtain coater, champflex coater, bar coater, dry coaster, overcoat coater, spray coater, spray coater, spray coater It is necessary to avoid raising the temperature so high that the organic polymer particles deform under the influence of heat to form a continuous film.

The amount of coating composition to be applied depends on its composition or paper quality and is therefore not standardized. However, in order to improve the printability for the transfer weight, the effective amount of coating is at least 0.5 g / m, preferably 3 to 30 g / m dry weight per side of the paper. The desired effects inherent in the invention cannot be achieved if less than 0.5 g / m xx of the coating composition is applied. The upper limit of the amount of coating is limited solely by economy. The coating layer can be formed by a single application of the coating composition or by two or more applications using the same or a different coating composition.

The coated synthetic paper thus obtained is subjected to a calender, a polishing calender and finishing treatments as are done for a conventional coating. In carrying out these treatments, such a high temperature and / or high pressure can be used that the polymer particles do not deform and form a uniform film.

The operation of the transfer printability according to the invention is not yet known. The theory we propose is that when a coating composition containing organic polymer particles is applied to the surface of the described synthetic paper, the organic polymer particles move toward the surface of the coating layer, resulting in the formation of micropores and a discontinuous coating layer which is effectively absorbed.

The coated synthetic paper of the present invention is highly advantageous because it has not only good transferability, but also good brightness or whiteness and opacity, good water resistance and good shape resistance, and because lightweight paper can be produced without giving up. desired properties of polyolefin paper.

The present invention will be explained in more detail with reference to examples which are illustrative but not limiting of the invention. In the examples, parts by weight and percentages are by weight unless otherwise indicated.

Examples 1-5 100 parts of polypropylene (1 (3 dl / g) and 1070 parts of methylene chloride were mixed to form a slurry. To the slurry was then added 1200 parts of an aqueous solution of polyvinyl alcohol containing 10% of polyvinyl alcohol (degree of polymerization 1400, saponification number 99%) and 2 parts of dodecylbenzenesulfonate. This mixture was placed in an autoclave and heated with stirring to obtain an emulsion. When the temperature of the emulsion had risen to 140 ° C, it was injected through a die to obtain a fibrous material. The resulting fibrous material was made into a 1 # aqueous suspension, which in turn was purified with a SPROUT WALDRON plate refiner. The specific surface area of the obtained synthetic fiber mass was 15 m / g. The mixture of synthetic pulp and natural cellulose pulp thus obtained, containing 20 parts of NBKP (bleached softwood sulphate pulp, CSP 420 cc) and 80 parts of LBKP (bleached hardwood sulphate cellulose, CSP 400 cc), was mixed together in the ratios shown in Table 1. . Then, 0.5 part of resin per 100 parts of pulp was added to obtain a slurry having a density of 0.5%. The paper sheet was prepared on a laboratory flat wire machine, after which the paper sheet was treated in a size press with polyvinyl alcohol (polymer grade 1700, saponification number 99 #) to obtain a base paper weighing 40 g / m 2.

Separately, 52.4 parts of No. 1 quality kaolin, 25.2 parts No. 2 grades of kaolin, 14.4 parts of aluminum hydroxide and 28 parts of polystyrene emulsion (deflection temperature 94 ° C at 18.5 Λ kg / cm and average particle size 0.5 microns) were dispersed in water with sufficient stirring in a high speed mixer to form a slurry. ) oxidized starch solution with an oxidation degree of 0.015 * 16 parts (solids content) of carboxylated styrene-butadiene copolymer latex (styrene / butadiene 60/40) to obtain a coating mixture with a final concentration of 58%. The coating mixture thus obtained was applied to the surface of the above-mentioned base paper in amounts of 7 g / m (felt side) to 9 g / m (wire side) dry weight with a wing coater. The coated paper was then dried and supercalendered. The different properties of the obtained coated papers are shown in Table 1.

ή1 56994

Control 1,100 parts of the same natural cellulose pulp as used in Examples 1-5 → 0.5 parts of resin and 2.5 parts of aluminum sulfate were mixed together to obtain a slurry having a density of 0.3 #. A base paper weighing 4-0 g / m 2 was prepared in the same manner as in Example 1.

Separately, 4-5 parts of No. 2 were dispersed in water. 1 quality kaolin, 35 parts No. 2 grades of kaolin and 20 parts of aluminum hydroxide with sufficient stirring with a high-speed mixer to obtain a slurry having a solids content of 67 # · To this slurry were added 7 parts (solids content) of oxidized starch (oxidation rate 0. 013) and 14 parts (solids content) in Examples 1-5) to obtain a coating mixture with a final concentration of 58 #. This coating mixture was applied to the surface of the above-mentioned base paper at a dry weight of 7 g / m (felt side) and 9 g / m (wire side) with a wing coater, after which the paper was dried and supercalendered to obtain a coated paper. The properties of this coated paper are shown in Table 1.

Control 2 This control is otherwise similar to control 1, except that the same base paper as in Example 3 was used. · The properties are also shown in Table 1.

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table 1

Example Control 12 3 4 5 12

Mass mixing ratio (#) NBKP 19 16 13 10 0 20 13 LBKP 76 64 52 40 0 80 52

Polyolefin pulp 5 20 35 50 100 0 35 Properties of coated paper

Density (g / cm 2) 1.09 1.05 1.00 0.93 0.83 1.13 1.05

Brightness (#) 78.9 79-5 83.5 85.6 89.8 76.6 82.1 Opacity (#) 80.4 83.8 87.1 90.8 95.5 78.8 85.6

Gloss (£) 56.0 55.8 52.3 50.4 49.5 40.6 36.5

Water resistance B A A A A D C

Printability transfer weight

for A A A A B B D D

(Note 1) Methods for judging paper quality (1) Brightness: Determined according to JIS P 8123 (the higher the value, the better the brightness).

(2) Opacity: Determined according to JIS P 8138 (the higher the value, the better the opacity).

(3) Gloss: Determined with a 75 ° Specular Glossmeter (the higher the value, the better the gloss).

(4) Water resistance: Two drops of water were dripped onto the coated surface, which was rubbed with a finger 15 times. The water droplets were then transferred to the surface of a black glass plate. After drying, the degree of whiteness on the plate was taken into account.

(5) Transferability: The transferability test was performed using

Rl Printability Tester (manufactured by AKIRA Industry Co.) with two printing units, one 0-li for the application of the source solution and 15 56994 for the application of the ink. The susceptibility of the paper ink was taken into account.

(Note 2) Grading of water resistance and transferability A: excellent B: good C: poor D: very poor

The above remarks also apply to Tables 2-5 ·

Compared to Control 1, the coated papers obtained in Examples 1-5 had excellent brightness, opacity, gloss and water resistance. In addition, the coated paper of the invention had excellent transfer printability.

In contrast, the coated paper according to Control 2 had very poor transfer printability.

In the following Examples 6-8, the coated papers were otherwise prepared in the same manner as in Example 3, except that different man-made pulps were used.

Example 6

A blend of 95 parts of high density polyethylene (melt index determined according to ASTM D 1238 6.0 g / min) as a polyolefin, 5 parts of polyvinyl alcohol (degree of polymerization 1400 and saponification number 99 #) as a hydrophilic polymer, 900 parts of hexane as a solvent and 3 parts of sodium dodecyl as a surfactant, emulsified under the same conditions as in Example 1.

The resulting emulsified dispersion was sprayed through a die to obtain a fibrous material. The specific surface area of the synthetic pulp purified with a p SPROUT WALDRON plate refiner was 15.9 m / g as determined by the BET method.

Example 7

Mixture containing 75 parts of polypropylene (/ ~ ^ _7 * 2.3 dl / g, (melt index 1.5 g / 10 min), 5 parts of polyacrylamide, 20 parts of ethylene-vinyl acetate copolymer (degree of polymerization 2000 and ethylene / vinyl acetate 85/15 ) and 30 parts of calcium carbonate powder, were emulsified under the same conditions as in Example 1. The resulting dispersion was sprayed through a die to obtain a fibrous material, and the specific surface area of the purified fibrous pulp was 21.5 m / g as determined by the BET method.

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Example 8

Mixture containing 77 parts of high density polyethylene (melt index 0.3 g / 10 min) and 18 parts of ethylene sodium acrylate copolymer (melt index 5 g / 10 min, ethylene / sodium acrylate 90/10) as polyolefins, 5 parts polyethylene oxide (degree of polymerization 100,000) , 900 parts of hexane as a solvent and 4 parts of sodium laurylbenzenesulfonate were emulsified under the same conditions as in Example 1. The resulting emulsified dispersion was sprayed through a die to obtain a fibrous material. After purification, the specific surface area of the synthetic polyolefin pulp was 18.9 m / g as determined by the BET method.

Checks 3-5

The various properties of the coated papers prepared according to Examples 6-8 and Controls 3-5 are shown in Table 2.

Table 2

Example Check 6 7 8 3 4 5

Mass mixing ratio (#) nbkp (#) 13 13 13 13 13 13 LBKP (#) 52 52 52 52 52 52

Polyolefin pulp (#) 35 35 35 35 35 35 Properties of coated paper

Density (g / cm5) 1.01 1.03 1.00 1.07 1.09 1.05

Brightness (#) 84.2 83.8 84.6 83.0 82.6 83-0 Opacity (#) 85.4 88.6 87.4 84.0 87.2 85.6

Gloss (#) 50.3 49.7 51.2 35.1 33.4 35.8

Water resistance A A A c c c

Printability for transfer weight A A A c c c __l___J__I_

Table 2 shows that the coated papers obtained according to Examples 6-8 had excellent gloss, water resistance and transfer printability compared to papers prepared according to Controls 3-5. In particular, the transferability of coated papers prepared according to Controls 3-5 was remarkably poor.

Other examples using synthetic polyolefin pulps according to other methods are shown in the following Examples 9 and 10.

Example 9

Synthetic polyolefin pulp was prepared by solution cutting methods.

5 parts of high density polyethylene (melt index 0.3 g / 10 min) was dissolved in 95 parts of xylene at a temperature above 100 ° C to obtain a 5% xylene solution, which was then gradually poured into cold ethanol, a non-solvent of polyethylene under high shear, effectively mixing with a juice mixer. The resulting pulp was treated with the same polyvinyl alcohol as used in Example 1 and purified with a SPROUT WALDRON plate cleaner. The specific surface area of the pulp was 6.3 m / g as determined by the BET method.

35 parts of the synthetic fiber pulp thus obtained were mixed with a natural cellulose pulp containing 13 parts of NBKP and 52 parts of LBKB to prepare a base paper in the same manner as in Examples 1-5 *

The coating composition containing organic polymer particles was then applied to a base paper sheet. The coating composition was the same as that used in Examples 1-5 and the coating method was also the same as described in Examples 1-5 ·

Example 10

The synthetic polyolefin pulp was prepared by a solution sputter spinning method. The solution obtained by dissolving 100 g of high density polyethylene (melt index is 6.0 g / 10 min) was dissolved in 1 liter of hexane with vigorous stirring at 180 ° C and sprayed through a die. The obtained endless fibrous material was cut to a length of about 5 mm and purified with a SPROUT WALDRON-1 plate cleaner by adding polyvinyl alcohol (same as in Example 1) and sodium dodecylbenzenesulfonate. The specific surface area of the pulp was 16.7

O

m / g determined by the BET method.

The coated synthetic paper was prepared in the same manner as described in Example 9 · 56994

Control 6 Coated synthetic paper was prepared using a base paper identical to Example 9 coated with a coating composition identical to that used in Control 1. Other conditions were the same as described in Example 9 *

Control 7 Coated synthetic paper was prepared using a base paper identical to that used in Example 10 and coated with a coating composition identical to that used in Control 1. Other conditions were the same as described in Example 10.

The different properties of the coated synthetic papers obtained in Examples 9 and 10 and Controls 6 and 7 are shown in Table 3. · From this table it is noted that the coated paper obtained in both Examples 9 and 10 was much better than the paper obtained in Controls 6 and 7 in terms of gloss, water resistance and transferability.

Table 3

Example Control 9 10 6 7

Mass mixing ratio (#) NBKP (#) 13 13 13 13 LBKP (#) 52 52 52 52

Polyolefin pulp (#) 35 35 35 35 Properties of coated paper Coated weight (g / m2) P / w 7/9 7/9 9/11 9/11

Paper weight (g / m) 56 56 60 60

Density (g / cm 2) 0.95 0.98 1.01 1.02

Brightness (#) 84.5 84.2 83.8 83.4 Opacity (#) 83 · 1 85 * 6 82.6 85.0

Gloss (#) 50.6 48.7 35.3 33.1

Water resistance AA D D

Printability for transfer weight_ A_ A Dc 56994

Examples 11-14

In each example, the 11-14 base paper was the same as in Example 3. · Four types of coating compositions were prepared containing a polystyrene emulsion identical to that used in Example 1 and applied to the base paper to obtain a synthetic coated paper. The mixture ratios of the coating compositions are shown in Table 4-.

Check 8

The base paper was the same as in Example 3 · A coating composition that did not contain a polystyrene emulsion was applied to the base paper to obtain a coated synthetic paper. The mixture ratios of the coating composition are shown in parts by weight in Table 4 ·.

The different properties of the coated synthetic papers obtained according to Examples 11-14 and Control 8 are shown in Table 4-.

Table 4-

Con- Example _roll____ 8 11 12 13 14-

Formulation

Well. 1 grade kaolin 4-5 4-2.7 36.0 22.5 0

Well. 2 grades of kaolin 34- 52.3 27.2 17.0 0

Aluminum hydroxide 21 20.0 16.8 10.5 0

Polystyrene 0 5 20 50 100

Oxidized starch 77777

Styrene-butadiene latex 14- 15 1 6 1 9 24- Properties of coated paper Coated weight (g / m2) F / W 9/11 8/10 7 · 5 / 9.5 5/6 3.5 / 4-.3

Paper weight (g / m 2) 60 58 57 51 4-7.8

Density (g / om5) 1.05 1.03 1.01 0.92 0.85

Brightness (#) 82.3 82.9 83.3 84-, η 84-.6 Opacity (#) 86.1 86.5 86.8 87.0 87.2

Gloss (#) 38.4- 4-5.5 51.1 52.6 52.5

Water resistance D B A A A

Printability

for noa D B A A A

18 56994

As can be seen from Table 4, compared to the control 8, the coated synthetic paper obtained according to Examples 11-14 had excellent transferability and good ink reception. In addition, it is noted that in Examples 11-14, the various physical and chemical properties were significantly improved and the improvements depended on the amount of polystyrene used. Improved transfer printability was achieved with a relatively small amount of coating composition containing polystyrene. This means that the weight of the coated synthetic paper according to the invention can be reduced without compromising other desired properties.

Examples 15-29

The base paper sheet was the same as in Example 12. Different coating compositions containing different organic polymers as shown in Table 5 were applied to the base paper sheet to obtain coated papers. Other conditions were the same as in Example 12. The transfer printability of the coated papers obtained according to these examples is shown in Table 5. · In these examples, the coated papers had improved transfer printability.

19 56994

Table 5

Eef- Mean- Pressure- lecture ·· byte

Organic polymer thermal particle transfer mode for total weight (yu) _

Example

15 Polyvinyl chloride 64 0.4 A

16 Polyethylene (L.D.) 45X 0.9 B

17 Polypropylene 99X 0.8 B

18 Ethylene-propylene copoly- 85X 0.8 B

meeri (15:85)

19 Poly-4-methyl-1-pentene 180 0.7 A

20 Polymethyl acrylate 87 0.4 A

21 Polyvinyl acetate 38 0.5 B

22 Ethylene-vinyl acetate copo- 40x 0.5 B

lymer (92: 8)

23 Ethylene-propylene mixed copoly- 65X 0.5 B

lymer (3:97)

24 Styrene-acrylonitrile copo- 92 0.3 A

lymer (76:24)

25 Styrene-maleic anhydride 140 0.3 A

dicopolymer (1: 1) (molar ratio)

26 Ethylene-maleic anhydride-170 0.5 B

copolymer (1: 1) (molar ratio)

27 Ethylene Acrylic Acid Copolymer 88 0.4 A

(90:10) sodium salt

28 Styrene-acrylonitrile itaco- 85 0.5 A

nic acid copolymer (92: 6: 2)

29 Styrene-acrylonitrile / ¾ - 80 0.5 A

hydroxyethyl acrylate copolymer (89: 6: 3: 2) 20 56994

Note 1 In Table 5, the polymer blend ratios are shown by weight, except in Examples 25 and 26.

Note 2 The deflection temperatures denoted by x are indicated at 2 at a pressure of 4.6 kg / cm, while temperatures without said sign are indicated at a pressure of 18.5 kg / cm, both temperatures being determined according to ASTM standard D 648.

Example 50, control 9

The coated papers in Example 30 were obtained using a first coating layer (bottom coating layer) and a second coating layer (top coating layer), each layer containing the various components shown in Table 6, on the same base paper as in Example 3.

In the control, the second coating layer does not contain a polystyrene emulsion. The amount of each component of the coating composition is expressed as dry weight. The properties of the obtained coated paper are shown in Table 6.

21 56994

Table 6

Example Control 30 9

First coating layer

Well. 2 grades of kaolin 75 75

Calcium carbonate 25 25

Sodium hexametaphosphate

Oxidized starch

Styrene butadiene latex 4 4

Second coating layer

Well. 1 grade kaolin 32.4 45

Well. 2 grades of kaolin 24.5 34

Aluminum hydroxide 15.1 21

Polystyrene 28 0

Oxidized starch

Styrene butadiene latex 16 14 2 Coated weight (g / m)

First coating layer F / W 6/8 6/8

Second coating layer F / W 3/5 3/5

Paper weight (g / m) 62 62

Density (g / cm 2) 1.03 1.08

Brightness (#) 81.8 81.1 Opacity (#) 86.8 86.0

Gloss (#) 58.3 42.5

Water resistance A D

Printability for transfer weight A C

Claims (12)

22 56994 A coated synthetic paper suitable for transfer printing and comprising a base paper sheet containing at least 5% by weight of a fibrous material made of a polyolefin pulp made of a polyolefin polymer and a hydrophilic polymer, and a coating layer formed on said base paper. surface, and made mainly of a binder component and a pigment component, characterized in that the amount of said binder component is in the range of 5 to 100 parts by weight per 100 parts by weight of said pigment component, and at least 5% by weight of said pigment component is organic polymer pigment a structural member selected from the group consisting of polyatyrene, polymethyl methacrylate, and copolymers of the foregoing with another vinyl monomer. Coated synthetic paper according to claim 1, characterized in that 5 ··> 95% by weight * of said fibrous material is formed from a polyolefin pulp. Coated synthetic paper according to claim 1, characterized in that said fibrous material is a mixture containing 5 ·· <95% by weight of polyolefin pulp and 95 ··. 5% by weight of natural cellulose pulp. Coated synthetic paper according to claim 1, characterized in that at least 10% by weight of said pigment component is an organic polymer pigment in the form of fine particles. Coated synthetic paper according to claim 1, characterized in that said pigment component is formed by a mixture of fine particles of an organic polymer pigment and an inorganic pigment. Coated synthetic paper according to claim 1, characterized in that the amount of said binder component is 8 to 35 parts by weight per 100 parts by dry weight of said pigment component. Coated synthetic paper according to claim 1, characterized in that said organic polymer pigment is formed by fine particles of an organic polymer having a deflection temperature higher than 30 ° 0 as determined according to ASTM standard D-648. 23 5 699 4 Coated synthetic paper according to claim 1, characterized in that said organic polymer pigment is formed by fine particles of an organic polymer having a deflection temperature higher than 50 ° C as determined according to ASTM standard D-648. Coated synthetic paper according to claim 1, characterized in that said organic polymer pigment is formed by fine particles with an average size of 0.1 to 1.0 microns. Coated synthetic paper according to claim 1, characterized in that the weight of said coating layer is at least 0.5 g / m dry weight. Coated synthetic paper according to claim 1, characterized in that the weight of said coating layer is 3 to 30 g / m dry weight. Coated synthetic paper according to claim 1, characterized in that said polyolefin fiber is made of fibrils and has a specific surface area of at least 0.7 m 2 / g. A process for producing a coated synthetic paper according to one or more of the preceding claims 1 to 12, which paper is suitable for transfer printing, characterized in that a base paper sheet is produced consisting of a fibrous material of at least 5% by weight made of polyolefin pulp and coated with at least one surface of the base paper with a coating composition substantially containing a binder component, wherein at least a portion of said pigment component is an organic polymer pigment in fine particles. 24 3 6394 FATENTKEA.V