JPH0839436A - Grinding monofilament - Google Patents

Abstract

PURPOSE:To provide a grinding monofilament excellent in breaking durability while having high grindability with strong stiffness. CONSTITUTION:In a monofilament of 1.5 to 3.0mm external diameter formed by melt spinning a composition compounding 10 to 30wt.% abrasive material grain of 180# to 60# grain size processing a surface coated with a silane coupling agent relating to a polyamide resin of 3.0 or more relative viscosity, at the time of melt spinning this monofilament, a hollow part of 0.1mm or more internal diameter further 0.2 times or less an external diameter is formed in a fiber axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a monofilament for grinding which is mainly used for grinding a surface of an object to be treated such as metal. More specifically, it has strong fluff, high grindability and durability against breakage. The present invention relates to a monofilament for grinding having excellent properties.

[0002]

2. Description of the Related Art Conventionally, in surface grinding in the process of manufacturing metal products such as iron plates and aluminum plates, a monofilament containing abrasive particles mixed with abrasive particles in a synthetic resin and melt-spun is used as a bristle material for flocking. Brush rolls are mainly used.By pressing this brush roll against an object to be processed and rotating it, metal products can be directly ground and polished, or scraps attached to the rolling roller can be scraped off. Work such as is being done.

In particular, in the roughing process of the object to be processed, in order to further enhance the grinding force, the particle size of the abrasive particles contained in the grinding monofilament is further roughened, and the outer diameter of the monofilament as the bristle material is increased. A larger version is used.

The synthetic resin material of the above-mentioned monofilament containing abrasive particles is a polyamide resin having excellent bending durability, specifically nylon 6, nylon 66, nylon 610, nylon 612, nylon 11 and nylon 12. Is mainly used.

[0005]

However, the monofilament for grinding made of polyamide resin is melted when its outer diameter (diameter) is set to a large diameter of, for example, 1.5 mm or more in order to enhance the grinding force. In the spinning step, voids (air bubbles) tend to be generated inside the monofilament, and in some cases, voids of about 1/3 of the outer diameter are generated, and when the monofilament is used as a brush roll bristle material, the voids There was a problem of causing breakage of the material.

That is, when a polyamide resin composition containing abrasive particles is melt extrusion spun from a spinneret having a diameter of 1.5 mm or more, it is sufficiently cooled to the inside of the monofilament in a take-up step such as water cooling. Therefore, it is difficult for the polymer to shrink due to the temperature difference between the surface of the monofilament and the inner layer, and as a result, the larger the outer diameter of the monofilament, the larger the voids.

When the abrasive particle-containing monofilament having such a void is used as a bristle material of a brush roll, for example, the void serves as a core to cause breakage from this portion, and the breakage occurs. This includes the drawback of extremely poor durability.

In order to eliminate the above void,
A method of strictly controlling the melt spinning temperature of the monofilament, cooling conditions and drawing conditions to reduce the temperature difference between the inside and outside of the monofilament, and by coating the abrasive particles with a silane coupling agent beforehand, Although methods such as increasing the adhesiveness with the material particles and suppressing delamination between the two have been considered, it is still difficult to sufficiently reduce the occurrence of voids particularly in large-diameter abrasive particle-containing monofilaments. Therefore, further improvement has been desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a monofilament for grinding which has strong fluffiness, high grindability and excellent breakage durability.

[0010]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors found that a polyamide resin having a specific relative viscosity was surface-coated with a silane coupling agent. When a large-diameter abrasive particle-containing monofilament is produced by melt-spinning a composition in which material particles are blended, by forming a hollow portion having an extremely small inner diameter in the axial direction of the monofilament, strong fluffiness is achieved. The inventors have found that the breakage durability is remarkably improved while maintaining the grindability, and arrived at the present invention.

That is, the monofilament for grinding of the present invention has a relative viscosity of 3.0 or more with respect to a polyamide resin,
Particle size 18 whose surface is coated with a silane coupling agent
A monofilament having an outer diameter of 1.5 to 3.0 mm formed by melt-spinning a composition containing 10 to 30% by weight of abrasive particles of 0 # to 60 # and having an inner diameter of 0. A hollow portion having a diameter of 1 mm or more and 0.2 times or less of the outer diameter is formed in the fiber axis direction.

The present invention will be described in detail below.

Examples of the polyamide resin used in the present invention include nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12 and their mutual copolymers. The viscosity (measured according to JIS K6810 98% sulfuric acid method) is preferably 3.0 or more.

If the relative viscosity of the polyamide resin is less than 3.0, the physical properties of the obtained abrasive particle-containing monofilament become brittle, and the durability when used as a brush bristle material is not preferable.

Specific examples of the abrasive particles to be blended with the above polyamide-based resin include alumina-based abrasive particles such as coke powder, bauxite, and alumina oxide, silicon carbide-based abrasive particles such as white silica stone, abrasive powder, and industrial materials. Examples include natural abrasive particles such as diamond, emery and garnet, carbide abrasive particles, zirconia abrasive particles and glass abrasive particles. Among these abrasive particles, JIS R600 is used because it can exhibit a particularly high grinding force.
It is necessary to use a particle size measured by the method 1 in the range of 180 # to 60 #. If the particle size is smaller than 180 #, the grinding force of the obtained abrasive particle-containing monofilament decreases, If it is too coarse, the melt spinnability of the monofilament containing abrasive particles is deteriorated, which is not preferable.

The above-mentioned abrasive particles enhance the adhesive force with the polyamide resin and suppress the generation of voids due to the delamination between the polyamide resin and the abrasive particles caused by the stretching during melt spinning. For this reason, it is important to use the one whose surface is coated with a silane coupling agent such as aminosilane prior to mixing with the polyamide resin. The amount of the silane coupling agent used here is 0.05 to 0.20% by weight with respect to the abrasive particles.
The degree is desirable in terms of improvement in adhesiveness and spinning stability.

The amount of the abrasive particles treated with the silane coupling agent to the polyamide resin is 10
Is preferably in the range of 20 to 25% by weight, and if it is less than 10% by weight, the grindability of the obtained abrasive particle-containing monofilament is lowered, and 30% by weight.
If it exceeds the range, adverse effects such as a decrease in strength of the abrasive particle-containing monofilament are brought about, which is not preferable.

The composition comprising the polyamide resin and the abrasive particles treated with the silane coupling agent is well mixed in a mixer such as a ribbon blender and then supplied to a usual melt extrusion spinning machine to perform melt spinning. In the melt-spinning step, the hollow spinning spinneret is used, and the inner diameter is 0.1 mm or more in the axial direction of the obtained abrasive particle-containing monofilament by appropriately adjusting cooling and stretching conditions. In addition, it is an important requirement to form a hollow portion having 0.2 times or less of the outer diameter.

The inner diameter of the hollow portion has a great influence on the fluffiness, grindability and breakage durability of the monofilament containing abrasive particles. If the inner diameter is less than 0.1 mm, the occurrence of voids cannot be sufficiently suppressed. If it exceeds 0.2 times the outer diameter, not only the bristles and grindability are deteriorated, but also when a monofilament containing abrasive particles is planted on the brush, it is hollow by a pressing attachment member such as a channel brush for fixing the hair material. This is not preferable because the portion is deformed by pressure and tends to impair the physical properties of the monofilament itself.

That is, the inner diameter is 0.1 mm or more and 0.2 times or less of the outer diameter, particularly preferably 0.15 to
By forming a hollow portion in the range of 0.3 mm in the axial direction of the abrasive particle-containing monofilament, outside air is supplied to the hollow portion during melt spinning of the abrasive particle-containing monofilament, and the inner and outer layers of the monofilament-forming polymer are supplied. Since the particles are uniformly cooled, the generation of voids due to the difference in temperature between the inside and the outside is significantly reduced, and the breakage durability of the obtained abrasive particle-containing monofilament is significantly improved.

Since the hollow portion formed has a small inner diameter, it does not adversely affect the strength and bending hardness of the monofilament, and the fluff strength and high grindability of the abrasive particle-containing monofilament remain unchanged. Will be maintained.

Therefore, the monofilament for grinding of the present invention has strong fluffiness, high grindability, and extremely excellent durability against breakage, and is ideal as a brush bristle material for grinding metal, stone, concrete surface and the like. Exhibit the desired characteristics.

[0023]

EXAMPLES Next, the construction and effects of the grinding monofilament of the present invention will be described in more detail based on examples.

With respect to nylon 612 having a relative viscosity of 3.5,
Toray Silicone Co., Ltd. silane coupling agent (HS6
020) was coated with 0.1% by weight of 80 # silicon carbide-based abrasive particles (manufactured by Showa Denko KK) in an amount of 25% by weight and melt-spun using a hollow spinneret having a diameter of 4.5 mm. -By stretching, a monofilament for grinding (A) having an outer diameter of 2.0 mm and an inner diameter (hollow diameter) of 0.3 mm was obtained.

Further, similarly, a monofilament for grinding (B) having an outer diameter of 2.5 mm and an inner diameter (hollow diameter) of 0.4 mm
I got

On the other hand, for comparison, a grinding monofilament having an outer diameter of 2.0 mm and an inner diameter (hollow diameter) of 0.3 mm (in the same manner as described above except that the treatment of the abrasive particles with the silane coupling agent is omitted. C) and an outer diameter of 2.5 mm,
A monofilament (D) for grinding having an inner diameter (hollow diameter) of 0.4 mm was obtained.

Further, the above-mentioned grinding monofilament (A)
Under the same conditions as above, except that the formation of the hollow portion was omitted, the same procedure was performed using a solid grinding monofilament (E) with an outer diameter of 2.0 mm and a solid grinding monofilament (F) with an outer diameter of 2.5 mm. Obtained.

Further, in the solid grinding monofilament E, the solid grinding monofilament (G) and the outer diameter of 2.5 mm are similarly used except that the silane coupling agent treatment is also omitted. A monofilament (H) for solid grinding was obtained.

Table 1 shows the results of evaluating the breakage durability and the fluff strength of each of these eight types of grinding monofilaments by the following methods.

(Evaluation Method of Breakage Durability) The breakage durability of the brush roller was evaluated by the following in-house forced test method. That is, the number of times the hair was broken was measured for each of the 50 samples by the 270 ° repeated bending method, and the average value and the variation rate of the number of bending cuts were obtained. The larger the number of times and the smaller the fluctuation rate, the better the breakage durability.

(Evaluation Method of Knotting Strength) Bending hardness, which is a measure of knotting strength, was evaluated. That is, two stainless steel rods having a diameter of 2 mm are arranged and fixed in parallel at an interval of 10 mm, a monofilament for grinding having a length of 50 mm is placed under the stainless steel rod, and hooked with a hook to bend the stress of pulling upward. Calculated as hardness.

[0032]

[Table 1] Breakage Durability Hair waist strength Sample No. Number of flex cuttings (% variation) (Bending hardness kg) (A) 241 (10) 3.7 (B) 214 (12) 8.6 (C ) 195 (17) 3.6 (D) 164 (16) 8.6 (E) 167 (20) 3.8 (F) 146 (19) 8.8 (G) 150 (23) 3.7 (H ) 125 (25) 8.7.

As is clear from the results shown in Table 1, the grinding monofilaments (A and B) of the present invention were broken as compared with the comparative grinding monofilaments (C to H) while maintaining a strong fluff. The durability is significantly improved.

[0034]

As described above, the monofilament for grinding of the present invention has strong fluffiness, high grindability, and extremely excellent breakage durability, and grinds metal, stone, concrete surface, etc. Demonstrate the ideal characteristics as a brush bristle material.

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Claims (2)

[Claims] 1. A polyamide resin having a relative viscosity of 3.0 or more and 10 to 30% by weight of abrasive particles having a particle size of 180 # to 60 # whose surface is coated with a silane coupling agent.
The outer diameter obtained by melt spinning the blended composition is 1.5 to 3.
A monofilament for grinding, which is a 0 mm monofilament, wherein a hollow portion having an inner diameter of 0.1 mm or more and 0.2 times or less of the outer diameter is formed in the fiber axis direction during melt spinning. 2. The inner diameter of the hollow portion is 0.15 to 0.3 mm
The monofilament for grinding according to claim 1, characterized in that