JPH06262145A - Doctor blade made of thermoplastic resin composite material - Google Patents

Abstract

PURPOSE:To provide a novel doctor blade made of a fiber reinforced resin composite material excellent in blade strength, wear resistance and heat resistance and using polyphenylene sulfide as a matrix. CONSTITUTION:In the doctor blade made of the fiber reinforced resin composite material sheet using polyphenylene sulfide as the matrix, by controlling the crystal size of the matrix resin to 50-80Angstrom , preferably 50-70Angstrom , the strength property or wear resistance performance of the fiber reinforced resin sheet is improved and the heat resistance of the sheet is improved by making the crystallinity >=35%. The product is used for various fields owing to the excellent performance of blade strength, wear resistance and heat resistance.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel doctor blade comprising a fiber-reinforced thermoplastic resin composite sheet. More specifically, it is preferable to use reinforcing fibers such as glass fiber and carbon fiber and a matrix resin, polyphenylene sulfide (PPS), which have little damage to the counterpart roller during use, and have excellent wear resistance and heat resistance. The present invention relates to a useful doctor blade comprising a fiber-reinforced thermoplastic resin composite material sheet in which is integrated.

[0002]

2. Description of the Related Art Many types of doctor blades are mounted on various rollers of an iron making machine or a paper making machine for the purpose of removing foreign matters adhering to the surface or draining water.

Such a doctor blade has been made of metal for a long time, but in recent years, a blade made of a fiber-reinforced resin composite material sheet is being used. As such a fiber-reinforced resin composite material sheet, a sheet material in which reinforcing fibers are hardened with a thermosetting resin typified by an epoxy resin is known, and recently, a fiber-reinforced composite material using a thermoplastic resin as a matrix has also been studied. ing.

It is known that a doctor blade made of such a fiber-reinforced resin composite material sheet having a thermoplastic resin as a matrix has less possibility of damaging a counterpart roller and high abrasion resistance. Even in the evaluation conducted by the present inventors, the abrasion resistance performance of the fiber-reinforced resin composite material sheet using polyphenylene sulfide (PPS) as a matrix is clearly superior to that of the fiber-reinforced resin composite material sheet using epoxy resin as a matrix. The same result was obtained in the evaluation of the actual machine installation on the roller for the papermaking machine.

[0005]

However, as the performance required for the doctor blade sheet material, plate rigidity,
High material performance is required for a wide range of items such as strength, abrasion resistance, heat resistance, etc. In crystalline thermoplastic resins such as polyphenylene sulfide (PPS), depending on the crystallization state, it can be used as a matrix. However, there is a problem that the performance of the composite material sheet is significantly different. For example, while a fiber-reinforced resin composite material sheet using amorphous polyphenylene sulfide as a matrix shows high bending strength, its heat resistance tends to be rather lowered. Therefore, the development of a doctor blade that is excellent in both of these conflicting performances is desired.

As a result of intensive research to solve the above-mentioned problems, the inventors of the present invention have controlled the crystallization state of the matrix resin constituting the composite material sheet within a specific range.
While satisfying each performance required as a doctor blade, it prevents damage to other rollers,
It was also found that a fiber-reinforced thermoplastic resin sheet for doctor blades having excellent wear resistance and heat resistance can be obtained,
The present invention has been completed.

[0007]

The present invention provides a doctor blade comprising a fiber-reinforced thermoplastic resin composite material sheet in which reinforcing fibers and polyphenylene sulfide (PPS) are integrated, and the crystal size of PPS which is a matrix resin is 50-80 Å, preferably 5
The present invention relates to a doctor blade comprising a fiber-reinforced thermoplastic resin composite material sheet controlled to 0 to 70 angstrom, and further, the crystal size of the PPS is 50.
The present invention relates to a doctor blade made of a fiber-reinforced thermoplastic resin composite material sheet having a crystallization degree of 35% or more and a crystallization degree of 35% or more and a thickness of -80 to 80 angstrom, preferably 50 to 70 angstrom.

The reinforcing fibers (reinforcing fibers) in the fiber-reinforced thermoplastic resin composite material sheet constituting the doctor blade of the present invention are carbon fibers, glass fibers, silicon carbide fibers, para-aramid fibers, etc. Fibers having high strength and high modulus are preferably used. These are often used alone, but two or more kinds can be used in combination. The form of the reinforcing fiber may be a short fiber or a long fiber which is a non-continuous fiber having a relatively large fiber length, but a mat of continuous fibers, a cloth or the like is particularly preferable.

Volume content (V) of the fiber in the fiber reinforced thermoplastic resin composite material sheet constituting the doctor blade
Although f) can be appropriately selected within the range of 1 to 70%, it is preferably 20 to 65% in the case of a mat or cloth of continuous fibers.

On the other hand, the matrix resin is generally "PP
It is a polyphenylene sulfide resin abbreviated as "S". This resin is a crystalline resin having excellent heat resistance and is commercially available under various trade names. Of these, non-crosslinkable polyphenylene sulfide resin is preferably used in the present invention.

In the course of research for solving the above-mentioned problems, the inventors of the present invention used a fiber-reinforced thermoplastic resin sheet, which is obtained by impregnating glass fiber cloth with polyphenylene sulfide and integrated it, by rapid heating and cooling in a double belt press molding apparatus or the like. Molded with a possible press molding apparatus, the resulting amorphous polyphenylene sulfide glass fiber reinforced sheet was heat-treated under various high temperature conditions, and various glass fiber reinforced resin sheets with different crystallized states of polyphenylene sulfide were prepared. . Then, regarding the bending elastic modulus, strength, wear resistance, and heat resistance of the sheet material required as the main performance of the doctor blade, the characteristic values of each sheet were measured (see Example 1 and Example 2 described later). ).

As a result, the crystal size of polyphenylene sulfide, which is the matrix resin, exceeds 80 angstroms, as can be seen from the fact that the bending strength greatly differs between Test Specimen 6 and Specimen 7 in Example 1, which will be described later. Then, it was found that the bending strength of the fiber-reinforced resin sheet began to significantly decrease.

The material strength (particularly bending strength) of this doctor blade is an item that greatly affects the achievement of thinning of the plate or high contact pressure with the mating roller, which is strongly desired for improving scraping performance. In the fiber-reinforced polyphenylene sulfide resin sheet, controlling the crystal size of the matrix resin to 80 angstroms or less, particularly 70 angstroms or less is an important factor in realizing a doctor blade having excellent strength.

Further, for example, the test piece 8 of Example 2 described later.
Also, as is clear from the test piece 11, when the crystal size of the matrix resin exceeds 80 angstroms, the abrasion resistance tends to obviously decrease, and in the fiber-reinforced polyphenylene sulfide resin sheet used as the base material for the doctor blade, the resin It is an important factor to obtain a doctor blade having both excellent blade strength and wear resistance performance, by controlling the crystal size of 80 angstroms or less, preferably 70 angstroms or less.

However, the crystallization rate of polyphenylene sulfide is high, and as shown in Example 1, if the heat treatment is carried out at the crystallization temperature of polyphenylene sulfide or higher, the crystal size thereof reaches 50 angstroms or more even under a relatively low temperature and short time heat treatment condition. Therefore, the crystal size of the matrix resin in the actual fiber-reinforced polyphenylene sulfide resin sheet is usually 50 angstroms or more. Therefore, the crystal size in the doctor blade of the present invention needs to be 50 to 80 angstroms, preferably 50 to 70 angstroms.

Furthermore, the heat resistance of the fiber-reinforced polyphenylene sulfide resin sheet in which the matrix is in an amorphous state is extremely low, and it is desirable that the polyphenylene sulfide resin be crystallized to some extent in the doctor blade application used at high temperature. This means that the test piece 3 and the test piece 4 or the test piece 9 and the test piece 10 of Example 1 are used.
It is obvious by comparing the heat resistance of. That is, when the matrix resin has a crystallinity of 35% or more, the heat resistance of the fiber-reinforced polyphenylene sulfide resin sheet is H.
When DT = 280 ° C. or higher, it exhibits heat resistance performance equivalent to that of other highly crystallized fiber-reinforced polyphenylene sulfide resin sheets.

As described above, setting the crystallinity of the polyphenylene sulfide to 35% or more is a preferable condition for heat resistant use of the glass fiber reinforced polyphenylene sulfide resin sheet. Further, the abrasion resistance of the sheet is also improved as compared with the amorphous fiber-reinforced polyphenylene sulfide resin sheet by setting the crystallinity of polyphenylene sulfide to 35% or more.

As described above, in the glass fiber reinforced polyphenylene sulfide resin composite material sheet used as the base material for the doctor blade, the crystal size of the matrix resin is controlled to 50 to 80 angstroms, preferably 50 to 70 angstroms. To do
By providing excellent strength or wear resistance as a doctor blade and further increasing the crystallinity to 35% or more, the heat resistance and wear resistance as a doctor blade can be improved.

Various methods can be adopted for producing the doctor blade of the present invention having the above-mentioned characteristics. Industrially preferable methods include continuous fiber cloth such as glass fiber and carbon fiber and polyphenylene sulfide. Of the film, cloth or powder, etc. are laminated, and the laminate is heated and pressed at a temperature above the melting point of polyphenylene sulfide to melt the resin and impregnate it into the cloth to form an integral sheet. Then, at that time, it is rapidly cooled after forming to form a composite material using a resin in an amorphous state as a matrix, and then heat-treated at a constant temperature and time to form a sheet in a predetermined crystalline state,
There is a method of cutting this into a predetermined shape.

[0020]

The doctor blade of the present invention is a fiber-reinforced thermoplastic resin composite material sheet constituting the doctor blade,
The constituent resin PPS has a specific crystal state, that is, a crystal size of 50 to 80 Å, and a crystallinity of 3
By controlling to 5% or more, the strength and abrasion resistance are remarkably improved, and the heat resistance is also improved. Moreover, the good heat resistance of the matrix resin polyphenylene sulfide, the effect of preventing damage to the roller, etc. It is a doctor blade made of a fiber-reinforced thermoplastic resin that has not been available in the past.

Therefore, the doctor blade according to the present invention is suitable for being used by being mounted on an iron making machine, a paper making machine, and various other rollers.

[0022]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

The method of measuring each physical property value and the like in the present invention is as follows.

(A) Abrasion amount: # 400 sandpaper was attached to the surface of a rotating disk having a relative speed difference of 16.5 m / min between the test piece and the disk, and 5 g / mm per sample piece cross section.
^A weight was applied so that a constant contact pressure of ² acted, and the test was performed with the test piece set so as to be perpendicular to the disk. In addition, in order to prevent the sandpaper from being clogged with abrasion powder, water was constantly flown on the friction surface. Further, in order to improve the accuracy of the difference in wear amount, the measurement was performed after reaching a stable wear amount region after the initial excessive wear (measurement of wear amount after 30 minutes from startup).

(B) Crystal state: The crystal state was analyzed by X-ray diffraction. X-ray measuring device is AD manufactured by Rigaku Corporation
-B was used. X-ray S. = 1/2 °, R.I. S. =
0.15 mm, S.M. S. The sample was irradiated through each slit of ½ °, and the reflection intensity at a reflection angle of 5 ° ≦ 2θ ≦ 40 ° was measured. The crystallinity was calculated from the integrated intensity of 11 ° ≦ 2θ ≦ 27 °, and the crystal size was calculated from the full width at half maximum of the maximum peak.

(C) Bending characteristics: The bending elastic modulus and bending strength were measured according to the three-point bending method of JIS K 7055 (bending test method for glass fiber reinforced plastics).

(D) HDT (heat distortion temperature): JIS
K 7207, the deflection temperature under load of cured plastic was measured according to the test method.

[0028]

Reference Example 1 This reference example is an example in which a conventional fiber-reinforced thermosetting resin sheet for a doctor blade and a fiber-reinforced thermoplastic resin sheet for a doctor blade having polyphenylene sulfide (PPS) as a matrix were compared and examined.

Glass fiber plain weave cloth (weight of 200 g /
A commercially available fiber-reinforced thermosetting resin sheet for doctor blades, in which 9 sheets of mm ² ) were hardened with an epoxy resin, was obtained and used as a test piece 1.

On the other hand, an equivalent glass fiber plain weave cloth (manufactured by Unitika Yum Glass Co., Ltd., H-201,
Fabric weight 204 g / m ² ) 9 sheets and polyphenylene sulfide film (manufactured by Teijin Ltd., 120 μm thickness) 10
The material in which the sheets are alternately laminated is 320 ° C., 30 minutes, 30 k
The test piece 2 was molded by hot pressing under a constant pressure of g / cm ² .

Regarding these test pieces 1 and 2,
Table 1 below shows the measurement results of the amount of wear measured according to the above-mentioned test method.

[0032]

[Table 1]

As shown in Table 1, even with a fiber-reinforced resin sheet made of the same reinforcing material, the abrasion resistance performance of the sheet greatly differs depending on the difference in matrix resin, and in the fiber-reinforced resin composite material sheet using polyphenylene sulfide as a matrix, The abrasion resistance is obviously superior to that of the fiber-reinforced resin composite material sheet having an epoxy resin as a matrix.

[0034]

[Example 1] Glass fiber plain weave cloth (manufactured by Unitika Yum Glass Co., Ltd., H-201, basis weight 204 g /
m ²⁾ between the two glass fiber unidirectional reinforcing plain woven cloth (Unitika Yu M. Glass Co., PR-600, weight per unit area 600 g / m ²⁾ Two glass fiber unidirectional reinforcing plain woven cloth (Unitika Yu M. Glass ( Ltd., PR-5
00, basis weight 500 g / m ² ) 1 sheet, and further, polyphenylene sulfide film (manufactured by Teijin Ltd., 28
0μm thickness) 2 sheets H201 / PPS film / PR6
00 / PR500 / PR600 / PPS film / H2
The materials laminated in the order of 01 are rapidly heated and cooled from room temperature to 320 ° C. and 320 ° C. to room temperature under a constant pressure of 30 kg / cm ² for 5 minutes by a double belt press molding machine to obtain an amorphous polyphenylene sulfide resin. A fiber-reinforced resin sheet having as a matrix was molded. The thickness of the sheet was 1.37 mm, and the glass fiber volume content (Vf) was 60%.

One side cut out from the sheet was used as a test piece 3, and each piece cut out from the sheet was heat-treated under various temperature conditions, and the following test pieces 4 to 8 were prepared depending on the heat treatment conditions. That is, a fiber-reinforced resin sheet having a non-crystalline polyphenylene sulfide as a matrix is kept at 150 ° C./23° C. for a fixed time (5 minutes)
Hold at a temperature of 0 ° C / 250 ° C and test piece 4 / test piece 6 /
A test piece 7 was created. Further, the fiber-reinforced resin sheet having the amorphous polyphenylene sulfide as a matrix was held at 150 ° C. for 6 hours to prepare a test piece 5,
Further, the fiber-reinforced resin sheet was held at 250 ° C. for 1 hour to prepare a test piece 8. The above temperature indicates the temperature of the sheet itself.

The test pieces 3 to 8 obtained as described above are
The crystalline state of the polyphenylene sulfide resin was analyzed by the above-mentioned method, and the bending properties were measured. The evaluation results are shown in Table 2 below.

[0037]

[Table 2]

In Table 2, the unit of crystallinity is%, and the crystallinity of polyphenylene sulfide is shown to be around 55% even in the completely crystallized state. The unit of the crystal size is angstrom, but the crystal size was not measured in the test piece 3 (* mark in the table). In addition, the display unit of the elastic modulus of bending property and the strength is both kg / mm ² .

From Table 2, when the crystal size of the polyphenylene sulfide resin exceeds 80 Å,
It can be seen that the flexural strength of the fiber-reinforced resin sheet is significantly reduced. Then, in the fiber-reinforced resin sheet having a polyphenylene sulfide resin as a matrix, the crystal size of the polyphenylene sulfide resin is 50 to 8
It is well understood that 0 angstrom, particularly 50 to 70 angstrom, is particularly important for ensuring the strength and physical properties of the doctor blade.

[0040]

[Example 2] Glass fiber plain weave cloth (manufactured by Unitika Yum Glass Co., Ltd., H-201, basis weight 204 g /
m ² ) 3 pieces of glass fiber unidirectional reinforced plain weave cloth (manufactured by Unitika Yum Glass Co., Ltd., PR-600, basis weight 600 g / m ² ) are sandwiched between ² pieces, and further polyphenylene sulfide film (made by Teijin Limited) (280 μm thickness) 4 sheets H201 / PPS film / PR600 / P
PS film / PR600 / PPS film / PR60
0 / PPS film / H201 laminated materials in this order,
Fiber-reinforced resin sheet using amorphous polyphenylene sulfide resin as a matrix, which is rapidly heated and cooled from room temperature to 320 ° C. and 320 ° C. to room temperature for 5 minutes under a constant pressure of 30 kg / cm ² by a double belt press molding machine. Was molded. The thickness of the sheet was 1.96 mm, and the glass fiber volume content (Vf) was 45%.

While preparing the test piece 9 from the sheet,
The sheet was heat treated at 150 ° C. for 5 minutes to prepare a test piece 10, and the sheet was heat treated at 250 ° C. for 1 hour.
Created 1.

The HDTs showing the wear resistance and heat resistance of the test pieces 3 to 5 and the test piece 8 shown in Example 1 and the test pieces 9 to 11 were measured. The results are summarized in Table 3.

The crystalline state of polyphenylene sulfide was measured in the same manner as in Example 1. In the test piece 9, the crystal size could not be measured like the test piece 3.

[0044]

[Table 3]

Claims (2)

[Claims] 1. A doctor blade comprising a fiber-reinforced thermoplastic resin composite material sheet in which reinforcing fibers and polyphenylene sulfide are integrated, wherein the crystal size of polyphenylene sulfide which is a matrix resin is 50.
A doctor blade comprising a fiber-reinforced thermoplastic resin composite material sheet controlled to 80 angstroms. 2. The doctor blade according to claim 1, wherein the crystallinity of polyphenylene sulfide is 35% or more.