JP2011156760A - Squeegee for screen printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a squeegee for screen printing, wherein when it is attached to a squeegee holder, its tip surface is not deformed, and straightness and edge accuracy of the tip surface are high. <P>SOLUTION: The squeegee for screen printing includes a metal-made support, and a plate-like squeegee body made of an elastic resin. The support and the squeegee body are integrally formed so that a part of the support is buried in the squeegee body, and a tip part is cut. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a screen printing squeegee.

In recent years, in the electronics field, a printing method has attracted attention as a manufacturing technique from the viewpoint of productivity and low environmental load, and a screen printing technique, which is one of the printing methods, has been incorporated into the manufacturing process.
For example, in the manufacturing process of a multilayer capacitor in which conductor layers and dielectric layers are alternately laminated, several tens to hundreds of times of multilayer printing are performed by screen printing with a printing film thickness of several μm. Dozens to hundreds of multilayer capacitors are manufactured simultaneously.
And in order to stabilize the quality of the product and improve the yield, achieve high printing accuracy, that is, make the printing film thickness uniform on the entire printing surface and not cause local printing defects. is important.

In order to achieve high printing accuracy in screen printing, generally, the printing pressure in the longitudinal direction of the screen printing squeegee and every time the squeegee is changed (pressing pressure of the contact portion with the screen) and the screen It is considered important to make the contact angle constant (uniform).
As a specific screen printing squeegee, for example, a screen printing squeegee in which one end of a plate-like squeegee body made of polyurethane elastomer is sandwiched between metal supports and the squeegee body is fixed to the support by bolting is used. It has been proposed (see, for example, Patent Document 1).

When screen printing is performed using such a screen printing squeegee, if the printing film thickness is controlled by several μm, the printing film thickness is not constant over the entire printing surface, and the film thickness varies from printing area to printing area. May occur.

In addition, when a conventional squeegee is used for many times of multi-layer printing, a linear protrusion may be formed on the substrate to be printed in the traveling direction of the squeegee, that is, a local printing defect may occur. It was.

JP 2000-272090 A

It was expected that the printing pressure of the screen printing squeegee and the contact angle with the screen were not uniform as the cause of the nonuniform printing film thickness on the entire printing surface, but the root cause was not clear.
Therefore, as a result of repeated research by the present inventors, the cause of the uneven printing pressure and contact angle is that when the squeegee body is fixed to the support body by bolting, the squeegee and the other parts are squeegeeed. Because the tightening pressure applied to the main unit is different, the degree of deformation of the squeegee main unit varies from part to part, and the tip surface of the squeegee main body is deformed so that it undulates, resulting in a decrease in the straightness of the front end surface. It became clear that
Therefore, the present inventor has intensively studied to solve this problem and completed a squeegee for screen printing in which the squeegee body is not deformed and the straightness of the tip surface is maintained when fixed to the squeegee holder. did.

On the other hand, it was considered that the problem of the formation of linear protrusions on the substrate was due to the presence of minute defects at the edge of the squeegee tip.
Accordingly, the present inventor has studied a squeegee tip processing method, and has completed a screen printing squeegee that has no missing edge and has high tip edge accuracy.

The screen printing squeegee of the present invention comprises a support and a plate-like squeegee body made of an elastic resin,
Both are integrally formed so that a part of the support is embedded in the squeegee body, and the tip surface of the squeegee body is a surface formed by cutting.

In the screen printing squeegee, the cutting process is preferably performed using a blade, and the support is preferably made of metal or resin.
In the screen printing squeegee, a through hole that serves as a positioning reference when being attached to the squeegee holder is formed in a portion of the support that is not embedded in the squeegee main body, and the cutting work is performed through the through hole. It is desirable that it is given on the basis of.

In the screen printing squeegee, it is desirable that a part of the support is bent.
It is desirable that at least the bent portion of the support is embedded in the squeegee body, and the bending angle of the bent portion of the support is 90 to 165 °.
It is desirable that the support is embedded so that the unbent portion is located in the center in the thickness direction of the squeegee body.

In the screen printing squeegee, the elastic resin is desirably a polyurethane elastomer, and the polyurethane elastomer is desirably a polyurethane elastomer having a polyester polyol as a polyol component.
The polyester polyol is preferably a mixture of 10 to 90% by weight of a polyester polyol composed of ethylene glycol, diethylene glycol and succinic acid and 90 to 10% by weight of a polyester polyol composed of neopentyl glycol, diethylene glycol and succinic acid.

Hereinafter, in the present specification, when simply expressed as “squeegee”, it means “screen squeegee” unless otherwise specified.

The squeegee of the present invention includes a support body and a plate-shaped squeegee body made of an elastic resin, and both are integrally formed so that a part of the support body is embedded in the squeegee body. Since no load is applied to the squeegee body during installation, the squeegee body will not be deformed even after being fixed to the squeegee holder, and the straightness (straightness in the width direction and tilting) of the squeegee body will not be deformed. (Straightness of direction) can be maintained. By using such a squeegee, screen printing can be performed with high film thickness accuracy on the entire printing surface.
Furthermore, since the front end surface of the squeegee body of the present invention is formed by cutting, there is no minute missing and high front end edge accuracy is maintained. Therefore, when the squeegee of the present invention is used, not only high film thickness accuracy is maintained on the entire printing surface as described above, but even when performing tens to hundreds of layered printing, The occurrence of linear protrusions can be avoided, and the problem of local printing failure can be solved.

Hereinafter, in the present specification, when the straightness of the front end face is simply described, both the straightness in the width direction and the straightness in the fall direction are indicated.

In the present invention, the straightness in the width direction of the tip surface of the squeegee body (hereinafter, also simply referred to as the width direction straightness of the squeegee body) is set so that the tip surface of the squeegee body faces the horizontal direction. Then, a portion of about 1 mm from the edge on the tip surface is scanned with a roughness meter over the entire length in the width direction, and the difference between the maximum value and the minimum value of the measured displacement amount is calculated.
In addition, the straightness of the tip surface of the squeegee body in the tilting direction (also referred to simply as the squeegee body tilt direction straightness) is laid down with the squeegee sideways so that the tip surface of the squeegee body faces in the vertical direction. This is determined by scanning a portion about 1 mm in the horizontal direction from the edge of the tip surface with a roughness meter over the entire length in the width direction and calculating the difference between the maximum value and the minimum value of the measured displacement.
In addition, when the shape of the squeegee body is not a plate shape (for example, in the case of a sword squeegee, etc.), it is necessary to slightly change the measurement points of the straightness in the width direction and the straightness in the fall direction. This will be described later.

Further, in the present invention, the tip edge accuracy of the squeegee body is observed by a microscope that slides in the width direction of the squeegee with the tip of the squeegee standing so that the tip is directed upward. At this time, using the edge of the tip of the squeegee as a reference line, the maximum value of the displacement (missing tip edge) observed with the microscope is calculated to obtain the tip edge accuracy.

It is a perspective view which shows typically an example of the squeegee for screen printing of this invention. (A) is the sectional view on the AA line of the screen printing squeegee shown in FIG. 1, (b) is a front view of the screen printing squeegee shown in FIG. It is a side part of another example of the squeegee for screen printing of this invention. It is a side part of another example of the squeegee for screen printing of this invention. (A) is a perspective view which shows typically another example of the squeegee for screen printing of this invention, (b) is the BB sectional drawing of (a). It is a side part of another example of the squeegee for screen printing of this invention. (A)-(d) is a side view which shows typically the shape of the front end surface vicinity of the squeegee main body which comprises the squeegee of this invention, respectively. It is a side view of an example of the cutting device of a squeegee tip. It is a side view for demonstrating the usage method of the screen printing squeegee of this invention shown in FIG. (A) is a side view which shows typically the squeegee manufactured in the comparative example 5, (b) is a front view of (a). (A)-(f) is a side view which shows typically the squeegee manufactured in Examples 1-8.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view schematically showing an example of a squeegee for screen printing according to the present invention, and FIG. 2A is a cross-sectional view taken along line AA of the squeegee for screen printing shown in FIG. FIG. 2B is a front view of the screen printing squeegee shown in FIG. 1.
In this specification, in describing the shape of the squeegee, in FIG. 1, the X-axis direction is the thickness (or thickness direction), the Y-axis direction is the width (or width direction), and the Z-axis direction is the height. (Height direction).

As shown in FIGS. 1 and 2, the squeegee 10 includes a metal support 11 and a plate-like squeegee main body 12 made of polyurethane elastomer, and a part of the support 11 is embedded in the squeegee main body 12. Is integrally molded.
Four through holes 13 a to 13 c are provided in a portion of the support 11 that is not embedded in the squeegee body 12.
Six through holes 14 are formed at equal intervals in the portion of the support 11 embedded in the squeegee main body 12, and the polyurethane elastomer constituting the squeegee main body 12 is also filled in the through holes 14.

In such a squeegee 10, a part of the support 11 is embedded in a squeegee main body 12 made of polyurethane elastomer, and both are integrally formed. Even if the squeegee body 12 is fixed, no load is applied to the squeegee body 12, and the distal end surface 12a of the squeegee body 12 is not deformed (bent), and the straightness of the distal end surface 12a is maintained.
Further, since the distal end surface 12a of the squeegee main body 12 is formed by cutting as described later, the distal end edge 12b has high accuracy and is excellent in local printing characteristics.
In the present invention, the front end surface of the squeegee main body is a side surface of the plate-like squeegee main body, which is a surface that faces the screen when in use. Moreover, the edge of the front end surface of a squeegee main body means the ridgeline part formed in the front-end | tip of a squeegee.

The through holes 13a to 13c can perform the following functions, respectively. In the present invention, each of the through holes 13a, 13b, and 13c is also referred to as a positioning circular hole 13a, a positioning oblong hole 13b, and a fixing hole (bucker hole) 13c.

・ Through hole 13a (positioning circular hole 13a)
The positioning circular hole 13a can function as a positioning reference in the width direction and the height direction with respect to the squeegee holder (see reference numeral 16 in FIG. 9) to which the squeegee 10 is attached.
That is, since the squeegee 10 is fixed to the squeegee holder with a bolt, for example, by adjusting the inner diameter of the positioning circular hole 13a to the bolt diameter, the squeegee is inserted into the positioning circular hole 13a. It can be attached at a predetermined position.
Further, even when the squeegee is attached to the squeegee holder in a manner in which the bolt is not inserted into the positioning circular hole 13a, the mounting surface of the squeegee holder or, if necessary, the aluminum interposed between the squeegee and the squeegee holder. If a protrusion is provided at a predetermined position of the block, the squeegee can be reliably attached at a predetermined position by fitting the protrusion into the positioning circular hole 13a.

・ Through hole 13b (positioning oblong hole 13b)
The positioning oblong hole 13b can function as a vertical positioning reference for the squeegee holder to which the squeegee 10 is attached.
That is, the diameter in the height direction of the positioning oblong hole 13b is matched with the bolt diameter used when the squeegee is attached, and the bolt is inserted into the positioning oblong hole 13b, whereby the squeegee is fixed in the height direction. It can be attached to a position.
On the other hand, in the positioning oblong hole 13b, the diameter in the width direction is set larger than the bolt diameter.
The squeegee of the present invention is manufactured by integrally forming a support and a squeegee body as will be described later. In this manufacturing process, heat treatment may be performed (the resin composition of the squeegee body material is cured). Therefore, when such a heat treatment is performed, the dimensions of the support may change slightly. Further, when the resin composition is cured, the resin composition contracts, and the dimensions of the support may change slightly depending on the stress at that time. However, even if the dimension of the support in the width direction changes before and after the integral molding, if the positioning oval hole 13b having an oval cross section (rounded rectangular cross section) is formed as a through hole that functions as a bolt hole, the positioning is performed. The squeegee can be fixed to the squeegee holder with a bolt while positioning in the height direction through the oval hole 13b.

・ Through hole 13c (fixing hole (stupid hole) 13c)
The fixing hole 13c has a larger opening diameter than the bolt diameter used when attaching the squeegee, and does not participate in positioning when attaching the squeegee to the squeegee holder, but simply used to fix the squeegee to the squeegee holder. Only fulfill the function of inserting.
When manufacturing the squeegee of the present invention, as described above, the dimensions of the support may change slightly, but due to this dimensional change, the position of the fixing hole 13c relative to the positioning circular hole 13a is slightly different from the design. Even if they deviate, the dimensional change can be allowed by making the opening diameter of the fixing hole 13c larger than the bolt diameter.

The formation positions and number of the through holes 13a to 13c depend on the design of the squeegee holder to which the squeegee 10 is attached, and are not particularly limited.

A through hole 14 is formed in a portion of the support 11 embedded in the squeegee body 12, and a polyurethane elastomer constituting the squeegee body 12 is also filled therein. By providing such a configuration, the adhesive strength between the support body 11 and the squeegee body 12 is further improved, and the support body 11 is more difficult to come off from the squeegee body 12. The pull-out strength from the squeegee body per width of the support is desirably greater than 0.5 kg / cm. This is because if it is less than 0.5 kg / cm, the squeegee body is displaced during printing, so that the accuracy of the squeegee mounting position is lowered and the printed film thickness becomes non-uniform.
The through holes 14 may be formed as needed, and the shape, number, and formation position are not particularly limited.

In the squeegee of the present invention, the straightness of the front end surface of the squeegee body is maintained before and after being attached to the squeegee holder. Therefore, it is desirable that the straightness is good in a state before being attached to the squeegee holder.
The straightness of the tip surface of the squeegee body is preferably 0.10 mm or less, more preferably 0.025 mm or less, as a difference between the maximum value and the minimum value of the displacement measured by the above method.
This is because if it exceeds 0.10 mm, it is difficult to control the printed film thickness over several μm over the entire printed surface.

On the other hand, the tip edge accuracy of the squeegee body of the present invention is preferably 0.050 mm or less, more preferably 0.010 mm or less, as a difference between the maximum value and the minimum value of the displacement measured by the above method. .
If the thickness exceeds 0.050 mm, the local printed film thickness becomes non-uniform, and when a multi-layer printing is performed, linear protrusions due to non-uniformly stacked ink are generated in the squeegee advance direction. It is.
In the squeegee of the present invention, the tip surface is formed by cutting in order to improve the tip edge accuracy of the squeegee body. The cutting process is desirably performed using a blade. This is because it is possible to reliably and easily form the tip surface having excellent straightness.
Moreover, it is desirable that the blade is a hard blade.
The above cutting process can be performed with a round blade, but when a round blade is used, if a chip occurs in a part of the cutting edge, the machining accuracy is lowered and the tip edge accuracy is lowered. This is because the work of checking and replacing the blade edge is complicated and inferior in productivity and uneconomical, whereas such a problem does not occur when a hard blade is used.
Moreover, when cutting using a cutter, it is desirable to perform this cutting using a so-called ultrasonic cutter that performs cutting while ultrasonically vibrating the cutter.
This is because, depending on the material and thickness of the squeegee body, cutting may be difficult, but even in such a case, the cutting can be reliably performed using an ultrasonic cutter.
The said cutting process can also be performed with the apparatus shown in below-mentioned FIG. When the apparatus shown in FIG. 8 is used, it is necessary to appropriately change the cutting angle of the blade 85 in accordance with the shape of the tip surface of the squeegee body.
When the tip surface is formed by polishing, minute irregularities are generated on the tip surface, leading to a decrease in edge accuracy. Therefore, formation of an edge by polishing is not preferable.

The cutting process of the tip surface of the squeegee body is desirably performed with reference to a positioning circular hole provided in the support. As described above, the squeegee of the present invention can be attached to the squeegee holder with reference to the positioning circular hole provided in the support body. This is because the positional relationship between the tip surface of the squeegee and the screen can be reliably controlled to the designed position.

The shape of the squeegee of the present invention is not limited to the shape shown in FIGS. 1 and 2 and may be, for example, the shape shown in FIGS.
3, 4, and 6 are side portions of another example of the screen printing squeegee of the present invention.
Fig.5 (a) is a perspective view which shows typically another example of the screen printing squeegee of this invention, (b) is the BB sectional drawing of (a).

1 and 2 has a flat plate shape. However, in the squeegee of the present invention, as shown in squeegees 20 and 30 shown in FIGS. Each part of 31 may be bent.
In this way, by bending a part of the support body, before and after embedding a part of the support body in the squeegee, particularly before embedding, the support body is prevented from being bent or bent and deformed. be able to. Therefore, the mounting accuracy (squeegee position accuracy) when fixing the squeegee to the squeegee holder can be improved.

Further, although the squeegee 20 and the squeegee 30 have different bending positions of the support, the squeegee 30 having a structure in which the bent portion of the support 31 is embedded in the squeegee body 32 is more desirable.
In the squeegee 30 having such a shape, since the bent portion of the support 31 is embedded in the squeegee body 32, in addition to the above effects, the pullout strength of the support 31 from the squeegee body 32 is improved. The effect of doing. By improving the pull-out strength, it is possible to prevent the squeegee body from shifting and to improve the mounting position accuracy, leading to uniform printing film thickness on the entire printing surface.
In the squeegee in which the bent portion of the support is embedded in the squeegee body, the shape of the squeegee holder is not limited. Also, both sides of the squeegee body can be used. As a result, the life as a squeegee is doubled and the economy is excellent.

Further, as shown in FIG. 4, in the squeegee 30 in which the bent portion of the support body 31 is embedded in the squeegee body 32, the unbent portion of the support body 31 is located in the center in the thickness direction of the squeegee body 32. Is desirable. In such a squeegee, when both sides are used, the position of the tip of the squeegee with respect to the screen is constant regardless of which side is used, and it is not necessary to readjust the squeegee mounting position when replacing the use side. .
In FIG. 3, reference numeral 22 denotes a squeegee body.

The shape of the squeegee of the present invention may have a shape like the squeegee 40 shown in FIGS. 5 (a) and 5 (b).
The squeegee 40 includes a support body 41 having a plurality of cut portions in a part of a flat plate-like support body, and bent portions 41a and 41b in which the portions provided with the cut portions are alternately bent in opposite directions. The bent portions 41 a and 41 b of the support body 41 have a structure embedded in the squeegee main body 42.
Such a squeegee 40 has the same effect as the squeegee 30 shown in FIG. 4, and in addition, the side view shape of the support body 41 is a right and left object, so that it is more suitable for use on both sides of the squeegee body. It becomes.

In the squeegee of the present invention, as shown in FIGS. 3 to 5, when a part of the support is bent, the bent angle of the bent portion (shown as θ in FIGS. 3 to 5) is 90 to 165 °. It is desirable that the angle is 90 to 135 ° in order to prevent the support from being bent or curved.
If it exceeds 165 °, the effect of bending a part of the support described above may not be enjoyed, and if it is less than 90 °, the strength of the bending point of the support may be lowered. .

The shape of the squeegee of the present invention may have a shape like the squeegee 50 shown in FIG.
The squeegee 50 includes a support body 51 having a wavy curved portion 51 a partially curved in a wavy shape, and the wavy curved portion 51 a of the support body 51 has a structure embedded in the squeegee main body 52.
The squeegee 50 having such a shape can also achieve the same effect as the squeegee 30 shown in FIG.

In the squeegees 20, 30, 40, and 50 shown in FIGS. 3 to 6, no through-hole is formed in the portion of the support that is embedded in the squeegee body. Similarly to the squeegee 10 shown in FIG. 5, a through hole may be formed in a portion of the support embedded in the squeegee body. It is because both are more reliably integrated by forming a through-hole.

In the squeegee of the present invention, an adhesive layer may be formed on the surface of the portion embedded in the squeegee body of the support. Thereby, the adhesive strength between the two is improved, and the support is more difficult to come off from the squeegee body.
It does not specifically limit as said adhesive agent, The thing normally used for a metal can be used. As specific examples, for example, urethane-based, polyester-based, silane-based, polyamide-based, and phenol-based adhesives can be used.
Further, a silane coupling agent layer may be formed instead of the adhesive layer.

In the squeegee of the present invention, a roughened surface may be formed on the surface of the portion embedded in the squeegee body of the support. This is because, by forming the roughened surface, the adhesive strength between the two is improved by the anchor effect, and the support is more difficult to come off from the squeegee body. In this case, by preventing displacement of the squeegee body, the accuracy of the squeegee mounting position is improved, and the printed film thickness is made uniform.
The method for forming the roughened surface is not particularly limited, and examples thereof include etching treatment, plating treatment, polishing treatment, oxidation treatment, and grinding treatment by sandblasting.

Moreover, in the squeegee described so far, the angle of the edge on the front end surface side of the squeegee body (the ridge line portion formed by the main surface and the front end surface in the plate-like squeegee main body: the portion indicated by 12b in FIG. 2A). However, in the squeegee of the present invention, the shape of the edge on the front end surface side of the squeegee main body is not limited to such a shape. It may be a simple shape.

FIGS. 7A to 7D are side views each schematically showing the shape of the vicinity of the front end surface of the squeegee body constituting the squeegee of the present invention.
The squeegee body 102 shown in FIG. 7A has a shape after integral molding. Cutting is performed on the distal end surface 102a by an ultrasonic cutter, which will be described later, to form a distal end edge 102b.
In the squeegee body of the present embodiment, when measuring the straightness in the width direction, a portion 1 mm from the tip edge 102b is measured, and when measuring the straightness in the tilt direction, the tip of the flat portion of the main surface is measured. A portion 1 mm from the edge 102b is measured.

The squeegee main body 103 shown in FIG. 7B is a so-called sword squeegee having a tip edge 103b processed into a pointed shape on the tip side. The leading edge 103b is formed by the apparatus shown in FIG.
In the squeegee body of this embodiment, when measuring the straightness in the width direction, the portion of the leading edge 103b is measured, and when measuring the straightness in the falling direction, a portion 1 mm from the leading edge 103b is measured. .

The squeegee main body 104 shown in FIG. 7C has a shape in which a C-chamfer is formed on one edge portion on the tip surface 104a side and a tip edge 104b is formed. The leading edge 104b is formed by the apparatus shown in FIG.
In the squeegee main body of this embodiment, when measuring the straightness in the width direction, the outermost portion of the tip surface that is a flat portion (a portion that has not been subjected to C chamfering) and that has been subjected to C chamfering. When measuring the straightness of the falling direction, and measuring the straightness of the tilt direction, the tip of the flat part of the main surface on the C-chamfered side (the part that has not been chamfered) A 1 mm portion is measured from the surface side portion.

The squeegee main body 105 shown in FIG. 7D has a shape in which C-chamfering is performed on both sides on the front end surface 105a side and a front end edge 105b is formed. The leading edge 105b is formed by the apparatus shown in FIG.
In the squeegee main body of the present embodiment, when measuring the straightness in the width direction, measure the 1 mm portion from the outermost portion of the flat portion (the portion where C chamfering is not performed) of the tip surface, and then fall down When measuring the straightness of the direction, a portion 1 mm from the portion closest to the front end surface is measured out of the flat portion of the main surface (the portion where C chamfering is not performed).

The shape of the squeegee main body shown in FIGS. 7A to 7D is formed by cutting.
The cutting process is desirably performed using a blade. This is because it is possible to reliably and easily form the tip surface having excellent straightness.
Moreover, it is desirable that the blade is a hard blade.
The above cutting process can be performed with a round blade, but when a round blade is used, if a chip occurs in a part of the cutting edge, the machining accuracy is lowered and the tip edge accuracy is lowered. This is because the cutting edge check operation and the replacement operation are complicated, inferior in productivity, and uneconomical, but such inconvenience does not occur when a hard blade is used.
Moreover, when cutting using a cutter, it is desirable to perform this cutting using a so-called ultrasonic cutter that performs cutting while ultrasonically vibrating the cutter.
This is because, depending on the material and thickness of the squeegee body, cutting may be difficult, but even in such a case, the cutting can be reliably performed using an ultrasonic cutter.

The said cutting process can also be performed with the apparatus shown in FIG. 8, for example.
FIG. 8 is an example of a schematic side view illustrating a state in which the tip 81 of the squeegee body is cut using the apparatus. The cutting device includes a setting jig 82 for placing the squeegee main body 87, a positioning jig 83 for determining the cutting position of the squeegee main body 87, and a squeegee being cut by pressing the placed squeegee main body 87 from above. A holding jig 84 for fixing the position of the main body, a cutter 85 for cutting the corner 81 of the squeegee main body, and a cutter fixing jig 86 for fixing the cutter 85 during the cutting are provided.

In the apparatus of FIG. 8, first, the squeegee main body 87 is placed on the set jig 82 whose placement position is determined by the set jig 82 and the positioning jig 83. Next, the position of the squeegee main body 87 is fixed by applying pressure from the upper surface of the mounted squeegee main body 87 with a pressing jig 84 and pressing it. The corner 81 of the squeegee main body 87 fixed in this way is cut using the blade 85 fixed by the blade fixing jig 86 (running the blade in the strip-shaped longitudinal direction) to produce a contact edge. By doing so, the squeegee body 87 having a desired tip edge can be manufactured.

Next, the material of the structural member which comprises the squeegee of this invention is demonstrated.
The material of the squeegee body is not particularly limited as long as it is an elastic resin, and examples thereof include polyurethane elastomer, silicone rubber, ethylene-propylene rubber, chloroprene rubber, butadiene rubber and the like.
Among these, polyurethane elastomers are desirable from the viewpoint of excellent mechanical strength and abrasion resistance.
In addition, as the polyurethane elastomer, a urethane prepolymer, which is a reaction product of a polyol component and an isocyanate component composed of polyester polyol or polyether polyol, cured with a curing agent can be used. From the viewpoint of superiority, it is desirable to use a polyester polyol as the polyol component.

As said polyester polyol, what dehydrated and condensed dicarboxylic acid and the glycol component can be used.
Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and the like. These may be used alone or in combination of two or more.
Among these, it is desirable to use succinic acid. This is because the physical properties of the squeegee body, particularly the solvent resistance, are excellent.

Examples of the glycol component include ethylene glycol, diethylene glycol, 1,4-butanediol, trimethylolpropane, neopentyl glycol, and the like. These may be used alone or in combination of two or more.
Moreover, what is necessary is just to make the said dicarboxylic acid and the said glycol component react at 150-300 degreeC by molar ratio 1.1-1.3.

As the polyester polyol, in particular, a polyester polyol composed of ethylene glycol, diethylene glycol and succinic acid (hereinafter also referred to as polyester polyol A) 10 to 90% by weight, and a polyester polyol composed of neopentyl glycol, diethylene glycol and succinic acid (hereinafter referred to as “polyester polyol A”). A mixture of 90 to 10% by weight (also referred to as polyester polyol B) is desirable.

More preferably, the mixture is a mixture of 20 to 80% by weight of polyester polyol component A and 80 to 20% by weight of polyester polyol component B.
It is because the organic solvent resistance of the polyurethane elastomer is extremely excellent by using such a mixture. The reason for this will be described below.

In the above polyester polyol A, the dicarboxylic acid is composed of succinic acid having a short chain length, and the glycol component is composed of diethylene glycol together with ethylene glycol having a short chain length. Therefore, the polyester polyol is composed of a methylene group of succinic acid and a methylene group of ethylene glycol. In addition to increasing the ester group density, the crystallinity is enhanced, and the ether group of diethylene glycol also enhances the crystallinity of the polyester polyol. Thus, the polyester polyol A has both high polarity and crystallinity, and gives a very high resistance to organic solvents to the resulting polyurethane elastomer.

On the other hand, the polyester polyol B has a neopentyl glycol component having a side chain methyl group symmetrically in the molecule instead of the ethylene glycol component in the polyester polyol A. However, since this neopentyl glycol has a relatively short chain length, the ester group density of the polyester polyol, and thus gives the polyester polyol B substantially the same polarity as the polyester polyol A. This lowers the crystallinity of the polyester polyol B and imparts hydrophobicity to the polyester polyol B.

As described above, the polyester polyol A having both high polarity and crystallinity has almost the same polarity, but by using the polyester polyol B having slightly low crystallinity, the crystallinity is maintained while maintaining the polarity as the polyester polyol component. While maintaining the organic solvent resistance of the resulting polyurethane elastomer, the compatibility with the polyisocyanate can be remarkably increased during the production.
Therefore, according to the above mixture, the polyester polyol and the polyisocyanate can be quickly and uniformly mixed, so that the polyurethane elastomer can be obtained by cast molding.

The isocyanate component is not particularly limited. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a mixture thereof, 4,4′-diphenylmethane diisocyanate (MDI), carbodiimide-modified MDI, hydrogenated MDI, And hexamethylene diisocyanate.

As the curing agent, a conventionally known curing agent can be used. Specific examples thereof include 1,4-butanediol, ethanediol, neopentyl glycol, diethylene glycol, bishydroxyethoxybenzene, hydroquinone-bis (2 -Hydroxyethyl) ether, 3,3′-dichloro 4,4′-diaminodiphenylmethane, bifunctional curing agents such as 4,4′-diaminodiphenylmethane, trimethylolpropane, glycerin, 1,2,6-hexanetriol , 1,2,4-butanetriol, trimethylolethane, 1,1,1-tris (hydroxyethoxymethyl) propane, diglycerin, pentaerythritol and other polyhydric alcohols, triethanolamine, triethanolamine, Isopropanolamine, diisopropa Amino polyhydric alcohols such Ruamin, and alkylene oxide at these polyfunctional compounds, e.g., ethylene oxide, propylene oxide, or amino polyhydric alcohols such as mixtures thereof comprising by ring-opening polymerization.
Among these, it is desirable that a dihydric alcohol and a trihydric alcohol are used in combination. However, trihydric alcohol, when used excessively, lowers the resilience of the resulting elastomer, and is usually used in a range of 40 mol% or less based on the total amount of dihydric alcohol and trihydric alcohol. It is desirable. In particular, a combination of 1,4-butanediol and trimethylolpropane is preferable.

Moreover, these hardening | curing agents are normally 1.00-1.50 so that ratio with the equivalent number of the active hydrogen which an isocyanate group, a polyester polyol, and the hydroxyl group or amino group of a hardening | curing agent may have with respect to the said polyisocyanate. Is blended into.

Although the material of the said support body is not specifically limited, For example, metal steel plates, such as plated steel plates, such as a steel plate and a galvanized steel plate, a stainless steel plate, a copper plate, and a phosphor bronze plate, are mentioned.
Since these metal supports are rigid, they are difficult to be deformed, machining such as cutting and deformation is relatively easy, and since they are inexpensive, they are economically advantageous.
In addition, the metal support is superior in adhesion to a polyurethane elastomer or the like as compared with other hard materials, and thus the support is difficult to be pulled out from the squeegee body.
Further, in the metal support, vibration due to sliding of the squeegee main body during use hardly occurs, and the printed film thickness is excellent.

In addition, as the material of the support, a rigid resin such as polycarbonate, acrylic, or glass epoxy can be used. Among these, it is desirable to use a glass epoxy resin because it is difficult to deform and is relatively easy to cut.

In the squeegee of the present invention, the size and the free end length of the support and the squeegee main body are not particularly limited, and may be appropriately selected according to the design of the screen printing apparatus to be attached. The general size is 5 to 20 mm in thickness, 30 to 90 mm in height, 100 to 300 mm in width, and about 10 to 30 mm in free end length. Of course, the size of the squeegee body according to the present invention is not limited to this size.

Next, a method for manufacturing the squeegee of the present invention will be described.
In the production of the squeegee of the present invention, both are arranged so that a part of the support is located in the molding space of the mold, and after the uncured resin composition is injected into the mold, the resin composition is cured. And by integrally molding the support and the squeegee body.

At this time, it is desirable that the support is subjected to predetermined processing in advance, that is, bending processing, formation of a through hole, or the like as necessary. If the part that is not embedded in the squeegee body is processed, it is possible even after the support and the squeegee body are integrally molded, but it is easier to perform the process before integral molding. This is because there is no risk of damage.
In addition, when a primer process or a roughened surface forming process is performed on a portion of the support body where the squeegee body is embedded, each process is performed before integral molding. Here, when the primer treatment is performed, the primer may be uniformly applied and dried using a brush, a sponge roller, or the like.

When the squeegee body is made of a polyurethane elastomer, a polyol component and an isocyanate component are reacted to form a prepolymer, and a prepolymer method in which the prepolymer is crosslinked and cured with a curing agent, or a polyol component, an isocyanate component, and a curing agent. A one-shot method can be employed in which they are mixed together and crosslinked and cured.
Here, when using a polyester polyol as a polyol component, it is desirable to employ the one-shot method, particularly when using a mixture of polyester polyol A and polyester polyol B. This is because the above-described polyester polyol has a relatively high viscosity.

The curing conditions at the time of the integral formation may be appropriately set according to the material of the squeegee body. For example, when a polyurethane elastomer having a mixture of the polyester polyols A and B as a polyol component is molded, 100 to 150 ° C. Then, it is desirable to cure in the mold for 20 to 120 minutes, and then to post-cure after taking out from the mold. Post-curing is desirably performed at 100 to 120 ° C. for 3 to 24 hours.

The support and the squeegee main body are integrally formed, and after the squeegee main body is taken out of the mold, cutting is performed to form the front end surface of the squeegee main body.
The cutting process is as described above.
By using such a method, the squeegee of the present invention can be manufactured.

Next, the usage method of the squeegee of this invention is demonstrated.
FIG. 9 is a side view for explaining a method of using the screen printing squeegee of the present invention.
In FIG. 9, the method of using the squeegee 30 shown in FIG.
The squeegee of the present invention is used by being fixed to a squeegee holder provided in a screen printing apparatus (not shown).
That is, as shown in FIG. 9, the squeegee 30 is fixed to the squeegee holder 16 by inserting the bolts 15 through the through holes 33 formed in the support 31. At this time, the squeegee 30 is fixed by interposing the plate-like aluminum block 17 between the squeegee holder 16. Further, the aluminum block 17 includes a through hole for inserting the bolt 15 at a position communicating with the through hole 33. In addition, the through-hole formed in the aluminum block 17 is a fool hole for inserting the bolt 15.
And the squeegee of this invention is used by operating a screen printing apparatus in the state attached to the squeegee holder.
In such a squeegee of the present invention, as already described, since no load is applied to the squeegee body when it is attached to the squeegee holder, there is a disadvantage that the squeegee body is deformed by bolting at the time of attachment. Absent.

In the usage mode shown in FIG. 9, the squeegee 30 is fixed to the squeegee holder 16 with the aluminum block 17 interposed. However, the aluminum block 17 may be interposed as required.
The aluminum block 17 has a function of defining the attachment position of the squeegee 30 in the thickness direction. When the aluminum block 17 is interposed, the tip surface of the squeegee body can be set at the same position as when the conventional squeegee shown in FIG. 10 is used. Therefore, when replacing with a conventional squeegee, it is not necessary to modify the screen printer main body.

The printing conditions performed using the squeegee of the present invention are not particularly limited, but the squeegee mounting angle is 60 to 80 °, the gap (gap between the printing medium and the screen) is 0.5 to 2.5 mm, and the squeegee push-in amount is 0.1. It can be suitably used when printing is performed under conditions of ˜0.5 mm and squeegee printing pressure of 2 to 6 kg / cm.

As described above, the squeegee of the present invention includes the support body and the squeegee body, and both are integrally formed so that a part of the support body is embedded in the squeegee body. When attaching, since no load is applied to the squeegee main body, the squeegee main body is not deformed even after being fixed to the squeegee holder, and good straightness can be imparted to the distal end surface of the squeegee main body.
Therefore, screen printing can be performed with high film thickness accuracy by using the squeegee of the present invention.

EXAMPLES Hereinafter, although an Example is hung up and demonstrated in more detail, this invention is not limited only to these Examples.

Example 1
In this example, a squeegee having the shape shown in FIG. The dimensional ratio is not the same as that of the squeegee of FIG.

Preparation of resin composition for squeegee body (1) An equimolar mixture of ethylene glycol (manufactured by Mitsubishi Chemical Corporation) and diethylene glycol (manufactured by Mitsubishi Chemical Corporation) and succinic acid (manufactured by Mitsui Chemicals, Inc.) of tetrabutyl titanate catalyst In the presence, the mixture was heated at 200 to 250 ° C. and reacted for 24 hours while dehydrating under reduced pressure to obtain a polyester polyol A having a terminal hydroxyl group and having a hydroxyl value of 57.7.

(2) Separately from (1) above, an equimolar mixture of diethylene glycol (Mitsubishi Chemical Co., Ltd.) and neopentyl glycol (Mitsubishi Gas Chemical Co., Ltd.) and succinic acid (Mitsui Chemicals Co., Ltd.) are mixed with tetrabutyl titanate. The mixture was heated at 200 to 250 ° C. in the presence of a catalyst and reacted for 24 hours while dehydrating under reduced pressure to obtain a polyester polyol B having a terminal hydroxyl group and a hydroxyl value of 53.4.

(3) Next, 75 parts by mol (53.39 parts by weight) of the above polyester polyol A and 25 parts by mole (18.24 parts by weight) of the above polyester polyol B are mixed, heated to 100 ° C., and stirred under reduced pressure. Dried.
To the polyester polyol mixture thus obtained, 4.11 parts by weight of 1,4-butanediol (Mitsubishi Chemical Co., Ltd.) and 0.56 parts by weight of trimethylolpropane (Mitsubishi Gas Chemical Co., Ltd.) are added, After premixing for 3 minutes, 27.75 parts by weight of MDI (4,4'-diphenylmethane diisocyanate, isocyanate amount 29%, Mitsui Chemicals, Inc.) modified with carboxylic diimide was added thereto, and an agitator SV manufactured by Shimazaki Seisakusho was used. The mixture was mixed at a constant rotational speed (450 rpm) until the mixture became uniform and transparent to obtain a resin composition for a squeegee body.

Production of support body Starting from a galvanized steel sheet (Kobe Steel Co., Ltd., Kobe Zinc Coat SECC-J2) that has been degreased to a thickness of 1.6 mm, the width is 200 mm and the height (Fig. 11 (a) ), H ₁ ) A 40 mm support was prepared.
Further, in this support body, through holes a to d are formed at positions of 28 mm from the lower end in the front view and at positions of 59.5 mm, 78.5 mm, 126.5 mm, and 145.5 mm in order from the left end. did. Here, the through hole a is a circular through hole having a cross section of 5 mm in diameter, the through holes b and c are circular through holes having a cross section of 5.5 mm in diameter, and the through hole d has a short diameter of 5 mm and a long diameter. This is a 7 mm oval through hole.

Integrated molding of support and squeegee body A mold for molding a squeegee body having a width of 205 mm, a thickness of 9 mm, and a height of 40 mm is prepared, and the support is disposed in the mold. The resin composition for a squeegee body was poured into a mold and cured at 110 ° C. for 1 hour, and then the squeegee body was removed from the mold.

Cutting of the front end surface of the squeegee main body The apparatus having the following configuration is arranged so that the free end length (Lf in FIG. 11 (a)) is 19 mm at the front end side of the squeegee main body removed from the mold. The squeegee was completed by cutting to form the leading edge.
(Configuration of cutting device)
Ultrasonic transmitter manufacturer: Nippon Emerson Corporation Main body: Lanson Power Supply 2000bdc (1100W)
Transmitter: Lanson converter CR-20 (20Hz)
Cutter holder: Titanium horn cutter for Lanson: Carbide cutter with 5 mm thickness Moving speed: 300 mm / sec

(Example 2)
A squeegee was produced in the same manner as in Example 1 except that an adhesive layer was formed on the portion embedded in the squeegee body of the support body before integral molding.
As an adhesive layer, a phenol adhesive (Chemlock # 218E, manufactured by LORD) was applied so that the thickness after drying was 20 μm, and then integrally molded.

(Example 3)
A squeegee having the shape shown in FIG. 11B was produced in the same manner as in Example 1 except that the portion of the support that was not embedded in the squeegee was bent before the integral molding.
The support was bent so that the length of the bent portion (Lc in FIG. 11B) was 6.6 mm and the bending angle (θ in FIG. 11B) was 90 °.

Example 4
A squeegee having the shape shown in FIG. 11C was produced in the same manner as in Example 1 except that the portion embedded in the squeegee of the support was subjected to bending before the integral molding.
The support was bent so that the length of the bent portion (Lc in FIG. 11C) was 6.6 mm and the bending angle (θ in FIG. 11C) was 90 °. In this support, the bent portion is located on the lower side.

(Example 5)
A squeegee having the shape shown in FIG. 11 (d) was produced in the same manner as in Example 3 except that the portion embedded in the squeegee main body of the support was subjected to penetration before the integral molding.
In addition, the through-hole of the part embed | buried under a squeegee main body was formed as follows.
That is, six through holes (diameter 3 mm) were formed at positions 10 mm from the lower end of the support (H ₃ in FIG. 11D) and at equal intervals in the width direction.

(Example 6)
A squeegee having the shape shown in FIG. 11 (e) was produced in the same manner as in Example 4 except that the portion embedded in the squeegee main body of the support was subjected to penetration before integral molding.
The penetration process was performed in the same manner as in Example 5.

(Example 7)
A squeegee having the shape shown in FIG. 11A was produced in the same manner as in Example 1 except that glass epoxy resin was used as the support material.

(Example 8)
A squeegee having the shape shown in FIG. 11 (f) was produced in the same manner as in Example 7 except that the portion embedded in the squeegee main body of the support was subjected to penetration before integral molding.
The penetration process was performed in the same manner as in Example 5.

(Comparative Example 1)
A squeegee was produced in the same manner as in Example 1 except that the tip surface of the squeegee body was polished after the integral molding.
The polishing process was performed using a MEDIA Squeegee Grinder (manufactured by Mino Shoji Co., Ltd.) with a standard polishing whetstone under the conditions of a grindstone rotating speed of 1700 rpm and a squeegee feed speed of 50 mm / sec.

(Comparative Example 2)
A squeegee was prepared in the same manner as in Comparative Example 1 except that glass epoxy resin was used as the support material and a roughened surface was formed on the portion of the support embedded in the squeegee body before integral molding. The roughening surface treatment was performed by a sandblast grinding process.

(Comparative Example 3)
A squeegee was produced in the same manner as in Example 1 except that the tip of the squeegee body was not processed after the integral molding.

(Comparative Example 4)
A squeegee was produced in the same manner as in Example 7 except that the tip of the squeegee body was not processed after the integral molding.

(Comparative Example 5)
FIG. 10A is a side view schematically showing the squeegee manufactured in Comparative Example 5, and FIG. 10B is a front view of FIG.
In the squeegee 70 shown in FIGS. 10A and 10B, a flat squeegee main body 72 is sandwiched between two aluminum support jigs 71 </ b> A and 71 </ b> B constituting the support body 71. The squeegee main body 72 is fixed to the support body 71 by tightening the bolts 75 that pass through 71A and 71B. The support jig 71A has a substantially rectangular shape in side view, the support jig 71B has a substantially L shape in side view, and a thread groove is cut in the inner wall of the through hole through which the bolt is inserted.

In this comparative example, a squeegee having the shape shown in FIGS. 10A and 10B was manufactured. The dimensional ratio is not the same as that of the squeegee 70.
(1) First, width (W in FIG. 10B) 200 mm, thickness (in FIG. 10A, t) 9 mm, height (H ₂ in FIG. 10A) 40 mm, tip surface A mold for molding a squeegee body having a chamfered shape with a side edge of R = 0.3 mm is prepared, and a resin composition for a squeegee body similar to that in Example 1 is poured into the mold. A squeegee body was produced by curing under the same conditions as in 1.
(2) Next, as shown in FIG. 10A, the squeegee main body 72 is sandwiched between the support jigs 71A and 71B, and the bolt 75 is tightened with a tightening torque of 1 Nm, thereby fixing the squeegee main body 72 to the support 71. The squeegee 70 was completed.
The support 71 has a height (H ₁ in FIG. 10A) of 59 mm from the front end surface of the squeegee main body 72 to the upper surface of the support 71, and the free end length of the squeegee main body 72 (FIG. 10A). Lf) is designed to be 19 mm, and the thicknesses of the portions holding the squeegee main bodies of the supporting jigs 71A and 71B (in FIG. 10A, T _{1 and} T ₂ ) are both 7 mm.
The bolt mounting position is 9 mm from the upper end in the front view of the support 71 (FIG. 10B), and is 59.5 mm, 78.5 mm, 126.5 mm and 145.5 mm in order from the left end. There are four locations.

(Comparative Examples 6-8)
A squeegee was produced in the same manner as in Comparative Example 5 except that the bolt tightening torque was changed to 0 Nm (Comparative Example 6), 2 Nm (Comparative Example 7), and 5 Nm (Comparative Example 8), respectively.

Evaluation of squeegee The squeegee manufactured in Examples and Comparative Examples was evaluated as follows.
In addition, about the squeegee manufactured in Examples 1-8 and Comparative Examples 1-4, the squeegee was fixed to the aluminum block of thickness 7mm, width 200mm, and height 25mm by bolting (refer FIG. 9), and evaluation after fixation A squeegee was used. At this time, the bolt tightening torque was 5 Nm.
In addition, as mentioned above, the through hole of the aluminum block interposed as needed when attaching the squeegee of the present invention to the squeegee holder is usually a fool hole, but in this evaluation, the thread groove to be screwed into the bolt The aluminum block provided with the through-hole (bolt hole) provided with was used.

(1) Tip edge accuracy of the squeegee body The tip edge accuracy of the squeegee body was observed with a microscope that slides in the width direction of the squeegee, with the tip of the squeegee standing upright. . Using the edge of the tip of the squeegee as a reference line, the maximum value of the displacement (missing tip edge) observed with a microscope was calculated and used as the tip edge accuracy.
The results are shown in Table 1.
(Observation conditions)
Microscope: VHX-600 (manufactured by Keyence Corporation)
Lens: VH-2450 (manufactured by Keyence Corporation)
Observation magnification: 450 times

(2) Straightness in the width direction of the tip surface of the squeegee body The straightness in the width direction of the tip surface of the squeegee body was evaluated by the following method using a surface roughness meter. In addition, about the squeegee of Examples 1-8 and Comparative Examples 1-4, the straightness before and behind fixing to an aluminum block, About the squeegee of Comparative Examples 5-8, the straightness before and after fixing a squeegee main body to a support body. Was measured.
(Surface roughness meter and measurement conditions)
Surface roughness meter: Mitutoyo Surf Test SV-3100H8
Contact terminal (stylus) shape: 60 °, tip R2μm
Contact terminal pressing force: 0.75mN
Scanning speed: 10mm / s

The squeegee (or squeegee main body) was allowed to stand so that the front end surface of the squeegee main body faced upward, and a portion 1 mm from the edge of the front end surface was scanned over the entire length using the surface roughness meter. . The difference between the maximum and minimum measured displacements was defined as the straightness in the width direction. The measurement points were set every 1 mm.
The results are shown in Table 1.

(3) Straightness of the tip surface of the squeegee body in the falling direction The squeegee (or the squeegee body) is laid down sideways so that the tip surface of the squeegee body faces the vertical direction, and the surface roughness Using a meter, a 1 mm portion from the edge of the tip surface was scanned over the entire length in the width direction. The difference between the maximum value and the minimum value of the measured displacement was defined as the straightness in the falling direction. The measurement points were set every 1 mm.
The results are shown in Table 1.
In this evaluation, straightness before and after fixing to the aluminum block is fixed for the squeegees of Examples 1 to 8 and Comparative Examples 1 to 4, and the squeegee body is fixed to the support for the squeegees of Comparative Examples 5 to 8. The straightness before and after was measured.

(4) (Adhesiveness) adhesion between the support and the squeegee body After the support is fixed, a pull-out test is performed in which the squeegee body is gripped and pulled out in the direction of 180 degrees to determine the pull-out strength per unit width. It was measured.
The results are shown in Table 1.

(5) Printing characteristics Screen printing was performed under the following conditions using the squeegees produced in the examples and comparative examples.
(Printing conditions)
Screen printing device (manufactured by Tokai Shoji Co., Ltd., Ceria SSA-PC660)
Screen frame: 300 x 300 mm (manufactured by Tokai Shoji Co., Ltd.)
Screen mesh: SUS # 400 (manufactured by Tokai Shoji Co., Ltd.)
Screen mesh opening: 120 x 120 mm
Ink: Nickel powder dispersion paste (Daiken Chemical Co., Ltd.)
Substrate: OHP film (Sumitomo 3M Limited)
Squeegee mounting angle: 75 °
Gap (gap between substrate and screen): 1.3mm
Squeegee push-in: 0.1mm
Squeegee printing pressure: 4kg / cm

The screen thickness was set to 2 to 4 μm and screen printing was repeated 10 times, and then the print thickness was evaluated with a micrometer (OMT-25, manufactured by Mitutoyo Corporation) over the entire print area. The thick part and the minimum print film thickness part were specified. The printed matter was cut in the longitudinal direction at each portion, and the cut surface was observed with a microscope to measure the printed film thickness.
The difference between the maximum print film thickness and the minimum print film thickness over the entire print area (Δt) is taken as the printing characteristics, and the results are shown in Table 1.
The smaller the value of Δt, the more uniform the printed film thickness.

(6) Local printing characteristics Screen printing was performed once with a printing film thickness of 5 μm under the above printing conditions. The substrate was cut in the width direction, and a cross-section of the substrate corresponding to the portion where the error of the leading edge of the squeegee was maximized was observed with a microscope.
Within the microscope field of view (width 0.7mm), local printing film thickness error due to edge error of squeegee, ie, convexity on the printed material that is not observed A rank, convexity less than twice the printing thickness Are observed as B rank, and those with a convexity exceeding twice the printed thickness are evaluated as C rank. The results are shown in Table 1.

As is clear from the results shown in Table 1, the use of the squeegees of Examples 1 to 8 improves both the printing characteristics and the local printing characteristics as compared with the case of using the squeegees of Comparative Examples 1 to 8. Became clear.
This is thought to be because the high straightness of the tip surface of the squeegee body secured when manufacturing the squeegee was maintained after being attached to the screen printing device, and the tip edge accuracy of the squeegee body was improved. .
In Comparative Examples 1 to 4, the local printing characteristics were deteriorated. This is considered to be because the edge accuracy of the tip is not sufficient when the tip of the squeegee body is polished and when not processed.
In Comparative Examples 5 and 6, although the degree of reduction in straightness of the front end surface after being attached to the screen printing apparatus was small, the uniformity of the printed film thickness was low. It was considered that this was because the support body could not hold the squeegee body securely.
In Comparative Examples 7 and 8, when attached to the screen printing apparatus, the straightness decreased and the printing characteristics also decreased at the same time. This was thought to be because the squeegee body was deformed by bolting.

10, 20, 30, 40, 50 Squeegee 11, 21, 31, 41, 51 Support 12, 22, 32, 42, 52, 102, 103, 104, 105 Squeegee body Lf Free end length

Claims (11)

A support and a plate-like squeegee body made of elastic resin are provided.
Both are integrally molded so that a part of the support is embedded in the squeegee body,
A squeegee for screen printing, wherein the front end surface of the squeegee body is a surface formed by cutting. The squeegee for screen printing according to claim 2, wherein the cutting is performed using a blade. The screen printing squeegee according to claim 1 or 2, wherein the support is made of metal or resin. A portion of the support that is not embedded in the squeegee body includes a through hole that serves as a positioning reference when attached to a squeegee holder.
The squeegee for screen printing according to claim 2 or 3, wherein the cutting is performed with reference to the through hole. The screen printing squeegee according to claim 1, wherein a part of the support is bent. The squeegee for screen printing according to claim 5, wherein at least the bent portion of the support is embedded in the squeegee body. The squeegee for screen printing according to claim 5 or 6, wherein a bent angle of the bent portion of the support is 90 to 165 °. The squeegee for screen printing according to claim 6 or 7, wherein the support body has an unbent portion located at a central portion in the thickness direction of the squeegee body. The squeegee for screen printing according to any one of claims 1 to 8, wherein the elastic resin is a polyurethane elastomer. The squeegee for screen printing according to claim 9, wherein the polyurethane elastomer contains polyester polyol as a polyol component. 11. The polyester polyol according to claim 10, wherein the polyester polyol is a mixture of 10 to 90 wt% of a polyester polyol composed of ethylene glycol, diethylene glycol and succinic acid and 90 to 10 wt% of a polyester polyol composed of neopentyl glycol, diethylene glycol and succinic acid. Squeegee for screen printing.

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