JPH0241480A - High-grade and high-accuracy screen printing - Google Patents

Abstract

PURPOSE:To accomplish the title printing improved in productivity and workplace environment by putting a thermoreversible polymer on the surface of a cloth to be printed and/or in a printing color paste and by making a printing on said cloth kept at temperatures higher than the phase transition temperature of said polymer. CONSTITUTION:Using a screen form of high mesh esp. >=200 mesh, a thermoreversible polymer, pref. a polymer <=40 deg.C in phase transition temperature comprising polyvinyl methyl ether and polyacrylamide derivative is put on the surface of a cloth to be printed and/or a printing color paste, and a printing is made in compliance with the conventional method on said cloth kept at temperatures higher than the phase transition temperature of said polymer. The thickening phenomenon due to thermogelation on the cloth will give sharpness of the edge of a pattern printed, and enable a low-viscosity color paste to be used in printing operations, thereby solving the cloggings of screen forms.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for imparting high-quality, high-precision designs onto fabrics by screen printing. For more details, see 1.
The screen-type mesh that has been widely used in textile printing and automatic screen printing, which has been widely adopted from C bundles, has a high density, promoting high quality and high viscosity of I'A patterns, and at the same time improving productivity and workability. This invention relates to a screen printing method for obtaining stable products with markedly improved environmental content.

[Prior art] It is well known that many technologies have been researched and developed to improve the quality and precision of national patterns produced by screen printing and have reached the current level.The main technologies are summarized as follows. The main points are measures in five areas. That is, (1) there is an improvement in the accuracy of the screen type.

Screen gauze, which started with silk fibers, was replaced by polyamide fibers and then polyester fibers due to its uniformity, stability, and strength, and the combination of multi- or monofilament yarns, weaving and processing conditions, or plate making, taking into account the opening or obstructing area. Conditions etc. have been improved,
Furthermore, suitable meshes have been selected and used in combination according to the pattern.
The combination of around 0 mesh and around 120 mesh is 140 to 160 mesh and 1 in automatic screen printing.
For example, a combination of 80 to 200 meshes is recommended. (2) Adjustment of squeezing conditions, such as gauge cross-sectional shape, hardness, angle, pressure, and speed, is important. It has been confirmed that a considerable improvement in accuracy can be achieved by adjusting the squeegeeing according to the rheological behavior of the colored glue used. In addition, for hand printing, where printing conditions vary greatly depending on individual differences, semi-automatic squeegee jigs or robots have been adopted. (3) Slight y4 adjustment of the flow behavior of the applied color paste is desired. For the main composition of colored paste, which is regulated by the dye and the fixing conditions or the printing method of anti-discharge dyeing, it is practical to improve the quality and precision by adding, for example, a small amount of a chemical that significantly improves its fluidity. It has become established. In addition, in order to emphasize the sharpness of the edges of the border between the undried color paste and the next color paste, a mutually incompatible combination of the two color pastes was selected and used. Countermeasures such as doing this are known. (4)-
Measures to accelerate the drying of color paste applied to nails are widely used.

It has been confirmed that the faster the drying speed of the printing color paste, the better the sharpness of the edges of the image, and in many cases, the composition of the color paste is prized depending on the drying time. It is also a well-known fact that forced drying methods such as heating racks or hot air blowers are standard operations in screen printing. (5
) There is a strong tendency to make preparation adjustments for the fabric to be printed at a high level. Emphasis has been placed on the preparation process of the fabric for printing, which had been ignored in the past, and thorough quality control of the fabric being printed has been carried out, such as minimizing changes in the texture of the fabric after printing.

[Problems to be solved by the invention] Despite the fact that high-quality printed products are produced through the technical measures mentioned above, as consumer needs become more sophisticated,
Printing with highly accurate and delicate designs has been required for high-quality, advanced fabrics.

In particular, in response to printing technology for printed wiring boards, there has been an increasing demand for application in the field of high mesh screen type printing, which is rapidly progressing. However, the screen type that can be adopted with the current textile printing technology level is up to 200. As mentioned above, in the case of hand-printing with a mesh size up to 5.0, particularly in the case of hand-printing where the screen pressure is low, aiming at high-quality printing, the density is only in a lower range for practical use. Therefore, in both manual and automatic screen printing, it is desirable to perform high-quality, high-precision printing using a high-density screen mold of 200 meshes or more, but there are the following basic problems. The current situation is that these problems are being pointed out and hindering their practical application. (1) In order to facilitate the permeation of the colored paste through the high mesh screen gauze and to ensure the amount of printing, it is necessary to significantly reduce the viscosity of the colored paste. Therefore, it is often necessary to modify the range that cannot be adjusted with conventional color paste compositions alone, and it is necessary to shift to 0, /W or W10 type emulsion systems similar to printing inks, purification of the working environment, and (2) In any case, in order to use low-viscosity colored glue, the edges of the printed colored glue should be made clearer to create highly accurate designs. Due to the purpose, it is necessary to suppress the spread of colored paste on the fabric, and it is necessary to adopt a forced drying method to accelerate drying of the printed colored paste on the fabric.

-Finally, hot air and heating table methods are known for drying printing fabrics, but while both are effective for drying the colored paste for printing, they are difficult to heat the colored paste on the screen mold during the printing process. It is extremely difficult to suppress this, and in particular, it becomes more difficult to prevent clogging of the screen gauze as the mesh becomes higher. (
3) In addition, in order to create a pattern consisting of multiple colors on a fabric without introducing a forced drying method, it is necessary to wait for the printing color paste to dry naturally before printing with the next color paste, and the number of colors increases. This poses a fatal problem in that the time required for printing with the corresponding colored paste increases significantly.

[Means for Solving the Problems] As a result of intensive research in order to solve the above problems, the present inventors have found that a high mesh screen type and a thermoreversible polymer compound exhibit a sharp phase transition in a relatively low temperature region. The present invention was achieved by focusing on the combined use of the thickening mechanism based on the thermal gelation phenomenon at high temperatures. ift
ft elementary conductors and partially saponified polyvinyl acetate are known, but these have phase transition temperatures in the range of 50°C to 85°C, which is a relatively high temperature range, and at the same time, the temperature at which thermal gelation appears is high. In contrast to thermoreversible polymers derived from these polymer compounds, which do not necessarily have sharp edges, the phase transition temperature of polyvinyl methyl ether and polyacrylamide derivatives produced by polymerization from monomers can be regulated extremely sharply. Furthermore, it has a built-in property that allows its transition temperature to be adjusted to below 40°C.

In addition to the above-mentioned polyvinyl methyl ether, the thermoreversible polymers that can be used in the present invention include polymers of N-isopropylacrylamide to N-yne 10-pylmethacrylamide,
Alternatively, polyacrylamide derivatives which are polymers such as copolymers consisting of both, N-n-propylacrylamide, N,N-diethylacrylamide, acrylamide having a pyrrolidyl group or piperidyl group, and tetrahydrofurfurylacrylamide can be mentioned. In order to improve the flow behavior of these polymers, the structure is not necessarily limited to a linear structure, but a branched structure or a partially crosslinked structure 3 may be introduced.

In addition, when using these polymers as a base paste for printing, it is possible to improve the printability of colored pastes by using them alone or in combination, and it is possible to mix and use 50% or less of a natural sizing agent by weight. However, since the phase transition temperature changes due to the addition of a coloring material or a third component,
It is necessary to investigate the phase transition temperature of the color paste in advance and adjust the temperature on the printed fabric surface within the appropriate temperature range. It is necessary to maintain the temperature below the transition temperature.

In addition, for cases where the stability of the color paste is difficult due to the combination of required components, or for combinations that make it difficult to adjust the desired phase transition temperature, the thermoreversible polymer is applied to the fabric to be printed, and a high mesh material is used. A method of printing with a low viscosity color paste of a drifting composition using a screen mold can be adopted.

In the screen printing system using a high mesh screen type, the present invention provides a coloring component by thermal gelation at a temperature higher than the phase transition temperature, in which the thermoreversible polymer compound is coexisted on either or both of the cloth to be printed and the barley color paste. This method achieves high-quality, high-precision printing by suppressing bleeding, and pads and dries the aqueous solution of the thermoreversible polymer compound on the fabric to be printed or the fabric that has undergone a preparation process in a conventional manner, or The aqueous solution is applied to the printing surface in combination with a coach ink, the dried fabric to be printed, a color paste prepared according to a conventional method, and a color paste made from the above-mentioned aqueous solution of a thermoreversible polymer compound. From inside to normal!
The JN colored paste has a cleansing effect on both untreated and surface-treated fabrics, while the colored paste containing a thermoreversible polymer compound has a clear effect on pre-treated fabrics. This means that it can be confirmed. A high mesh screen type is used for the printing system set by one or both of these, and printing, drying, fixing and post-printing are carried out according to conventional methods on the fabric maintained above the phase transition temperature of the thermoreversible polymer. When processing,
The viscosity of the A coloring paste used in this process is approximately 10,000 to 15.0 in conventional printing systems.
OOcps, 4.00 for flat type automatic screen printing
0 to 7,000 cps, rotary type automatic screen printing is not restricted to 2,000 to 4,000 cps, because the bC printing system was required to emphasize the sharpness of the edge of the design. This is because the viscosity of the color paste can be easily replaced by a thickening phenomenon due to thermal gelation at the phase transition temperature in the presence of the mature reversible polymer f-hybrid.

Therefore, if the fabric to be printed containing a heat-reversing polymer compound having a phase transition temperature corresponding to the specified temperature of, for example, 40°C or less, which does not cause any significant hindrance to the working environment of -a, is maintained at a predetermined temperature, The viscosity of the color paste maintained below the phase transition temperature is sufficient by prioritizing only the screen-type permeability, and the coexistence of a thermoreversible polymer compound in the color paste is not necessarily an essential condition. Conversely, if there is no thermoreversible polymer on the fabric to be printed, it goes without saying that it is a necessary condition for the thermoreversible polymer to coexist in the color paste. By coexisting thermoreversible polymers on both sides of the color paste, the same effect can be achieved.
Effects can be obtained. In particular, in the case of manual printing, printing work at 20°C to 25°C on the printed fabric, which is desired from an occupational safety and health perspective, can be achieved by keeping the color paste temperature below 20°C by air-cooling. This provides the advantage of being able to easily apply highly accurate patterns. Of course, since printing is done using low-viscosity colored pastes at low temperatures, clogging of the screen type has been eliminated, and bleeding in the heavy color gamut due to wet-on-wet printing has been greatly improved. It was confirmed that this greatly contributed to process rationalization. After the printing process, drying, fixing treatment and post-treatment are carried out according to conventional methods.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A piece of sateen with a set diameter prepared by scouring and bleaching in a conventional manner was spread on a heating stand adjusted to 30°C, and a T-NO350T (NBC Kogyo (4 wood, polyester monofilament wire diameter 35μ) was prepared.
Thickness, 350 mesh/2.54 (to), thickness 66μ,
Opening 38μ, opening area 27 ag')
Po1a was created using a screen mold normally made using
, r Brown RXL (CGY) 5% by weight, High Printer QC-I Special ((manufactured by Kikuchuo Giken, fluidity modifier) 1% by weight, and High Printer QC-S (
(41 manufactured by Chuo Giken, moisturizing agent) The following 3 containing 2% by weight
Print the seed colored paste, dry it, steam it at 100°C for 30 minutes, finish it by post-processing, and compare its suitability for printing. The three base glue compositions are a 3% by weight aqueous solution of high viscosity sodium alginate;
70 parts used (referred to as A glue.Appearance viscosity 8.0OOc)
ps), using 20 parts of the same (B glue, 1100 cps) and using 50 parts of a 20% by weight aqueous solution of N-isopropylacrylamide polymer with a molecular weight of 300.000 (C glue, 1,
9 AillJl, which was used after adjusting 1liJ with 100cps), is difficult to print and it is impossible to compose a design.

Some of the transparent parts of the color paste are also very blurred, and the clogging is so severe that it cannot be used for practical use.Ba has good screen transmission, but the printing color paste has a large bleed, and the outline of the design is not visible at all. It is unclear. Although it can be confirmed that increasing the temperature of the heating table tends to suppress bleeding, it is impossible to put it into practical use because clogging occurs frequently. On the other hand, the screen transmittance of C glue is extremely high, and the thickening effect corresponding to the thermal gelation on the fibers makes it possible to form sharp designs into ellipses, and to obtain printing with excellent quality and precision. Of course, in the case of C glue, if the temperature of the hot stand is increased or forced drying such as hot air is applied, the transmittance of the colored glue will decrease and clogging will occur.

Similar behavior was observed with T-NO250HD <polyester hexafilament 20 denier, 250 mesofilament, thickness 8
This was also confirmed when using a screen mold made from 0μ, opening 57μ, opening area 31%).

Example 2 - part of the set diameter satin used in Example 1 was reduced to 300 in terms of molecular weight.
．． 5 of 000 N-iso-10-vinyl acrylamide polymer
Immerse in a wt% aqueous solution at room temperature, squeeze to a squeezing rate of 110%, dry and finish at 100°C according to the usual method. 9. Place the treated fabric on a heating stand set at 30°C, and use T-NO420.
T (Using polyester seven filament wire diameter 35μ,
420 mesh, thickness 72μ, opening 25μ, obviating area 18%) was used in Example 1 to print 3 types of color pastes adjusted to 25°C using a screen mold, dry, and dry at 100°C for 30 minutes. It was steamed and post-treated and finished according to conventional methods. With A glue, it is impossible to print at all, and clogging occurs after one scouring, but with B glue, the screen penetration is relatively good, and the edges of the printed design become clear.

It can be seen that C glue exhibits the same behavior as in Example 1, and the sharpness of its design is further emphasized.

Example 3 A mercerized high-density cotton Burberry prepared according to a conventional method is spread on hot white clay adjusted to 35°C. T-
The following two colors, D and E, were prepared at 25°C using a screen mold made of NO225HD (polyester monofilament 22 denier, 225 mesh, thickness g 78), oathing 65μ, oering area 33%). The paste is printed, fixed by a conventional method, and finished by post-processing.

Color paste composition is K; i y a c i o n Re
d P-28 (KYK) 2% by weight, urea 5%
, Acidic Sodium Carbonate 3%, High Printer QC-
Contains 1% I Special 1wt and 50wt% base glue.

What about D-glue? L-forming agent 5% by weight, water 25% by weight and kerosene 70%
The base glue is a so-called half emulsion containing 5% by weight of a low viscosity sodium alginate aqueous solution, which is the same as the emulsion consisting of 30% by weight of polyvinyl methyl ether. Comparing the results of both printings, the screen permeability of D paste was significantly reduced, and at the same time, the printed design was bleeding severely. On the other hand, the screen transparency of E glue is good, and high-quality and highly accurate designs can be obtained.

Example 4 The printed fabric of Example 3 was pretreated with a 3% by weight aqueous solution of N-isoalrobylacrylamide with a molecular weight of about 2 million yen, and then
9. Glue D and E glue from Example 3 were diluted to twice the volume with thin glue, adjusted to 25°C, printed, dried, and steamed at 100°C for 10 minutes. Post-processing and Finishing 9 In both cases, a printed product with a high-quality, high-precision pattern is obtained.Example 5 Polyester satin prepared in a conventional manner was stretched at 25°C, and the temperature was adjusted to below 20°C.Resolin Blue FBL (BY
>3% by weight, High Printer PCA-BC (manufactured by 11 Chuo Giken, 1-Dense dye for ITs) 2% by weight, 5 High Printer QC-52% by weight, and two types of glue, F glue and Ggl1, consisting of 60% by weight of base glue. 1" -N O2251-
Printed with a screen mold using ID, dried,
High temperature steaming is carried out at 175°C for 7 minutes, followed by post-treatment and finishing according to conventional methods.・Locust bean gum 10% by weight aqueous solution,
Glue F, which is made of a base glue containing 5% by weight of high ether 1% CMC and 2% high viscosity sodium alginate by weight, has poor screen permeability, and furthermore, the color tearing at the edges of the printing color paste is significant. On the other hand, c IJI, which uses a 20'Eft3j% aqueous solution of poly N-isopropylacrylamide with a molecular weight of 750,000 as the base glue, has good screen permeability.
It can be seen that the sharpness of the printed design is also sharp, making it suitable for high-quality, high-precision textile printing. The same behavior is observed with alkali-depleted polyester decine.

Example 6 It was immersed in the satin and dene-containing poly N-isopropylacrylamide used in Example 5, squeezed to a squeezing rate of 80%, dried, and spread on a printing stand adjusted to 30°C to produce T-NO350'. F glue and G glue are printed using a screen mold made using 1. Either way, you can get a clear pattern. In particular, in the case of G glue, a printed product of even higher quality than that of Example 5 can be obtained.

[Effects of the Invention] According to the method of the present invention, it is not possible to apply a high-quality, high-precision pattern to a fabric using a low-viscosity printing base and a high-mesh screen mold.

In addition, forced drying of the printing paste and addition of organic solvents can be omitted, and it has been confirmed that this greatly contributes to significantly advancing production and environmental purification.

In addition, the thermoreversible polymer compound used has extremely good solubility in water below the phase transition temperature, which greatly simplifies the cleaning process in post-treatment, significantly reducing water usage, and reducing wastewater to the phase transition temperature. It has been found that each time the temperature is heated, the thermoreversible polymer C arsenic compound contained therein precipitates out, making it extremely advantageous to separate and remove it.

Procedural amendment ■ - Indication of status 1986 Patent Application No. 186652 2, Title of invention High quality, high precision screen printing method 3, Name of documents related to amendment (1) Request for application examination (2) Mei Lung 1 4. Relationship with the case of the person making the amendment Patent applicant: 2-50 Toyota 2-chome, Hino-shi, Miyako 191 Patent applicant NUBC Industry Co., Ltd. 6, Part 2 of the statement of contents of the amendment, Patent claim Correct the range as follows.

``Using a screen mold with a high mesh of 200 meshes or more, polymethyl ether and polyacrylamide derivatives having a phase transition temperature of 40°C or less are used as main components on the surface of the printed fabric or in the printing paste, or both. High-quality printing, characterized by printing according to a conventional method on a printing target fabric in which a thermoreversible polymer compound is present, and the temperature is maintained at least at a temperature higher than the phase transition temperature of the thermoreversible polymer compound;
High-precision screen printing method,

Claims (1)

[Claims] 1. Using a high-mesh screen type, a thermoreversible polymer compound is allowed to coexist on either or both of the surface of the fabric to be printed and the color paste for printing, and at least the thermoreversible polymer compound is A high-quality, high-precision screen printing method characterized by printing according to a conventional method on a printing target fabric maintained at a temperature above the phase transition temperature. 2. High mesh screen type mesh is at least 2
00 mesh or higher, the high-quality, high-precision screen printing method 3 according to the first item of the patent claim, which has a thermoreversible polymer compound having a phase transition temperature of at least 40° C. or lower, containing polyvinyl methyl ether and polyacrylamide derivatives as main components. A high-quality, high-precision screen printing method according to claim 1.