JP2003269035A - Polyacetal resin door roller - Google Patents

Abstract

(57) [Summary] (Modifications) [Problem] To provide a polyacetal resin door roller that can suppress compression deformation even when used for a long time as a door roller such as a sash or a hinged door, and can improve the opening and closing traveling. SOLUTION: As a polyacetal resin door roller 1, which is effective as a door roller such as a sash or a hinged door, a polyacetal resin composition is molded by an injection molding machine, and the obtained door roller is heated to 23 ° C.
(Humidity 50%) in a constant temperature room for 48 hours, the spherulite size is 0.001 to 10 μm, and the heat of fusion is 130 to 1
It is characterized by being 50 J / g.

Description

Detailed Description of the Invention

[0001]

The present invention has a spherulite size of 0.00.
The present invention relates to a door roller made of polyacetal resin having a thickness of 1 to 10 μm. More specifically, the present invention provides a door roller made of a polyacetal resin that is less likely to be deformed even when used for a door roller such as a sash or a swing door for a long period of time.

[0002]

2. Description of the Related Art Polyacetal resins are widely used for mechanical parts in the fields of automobiles, electronic / electrical fields, building materials, etc. because of their excellent mechanical strength, creep resistance and slidability. When used in these mechanical parts, creep resistance is important from the viewpoint of durability of the mechanical parts. When a door roller made of polyacetal resin having poor creep resistance is used for a long time in a sash, a hinged door, etc., the door roller itself is largely deformed and the open / close running property is deteriorated.

In order to solve these problems, conventionally, the number of door rollers attached to a sash or hinged door is increased,
It has been supported by reinforcing design such as increasing the thickness of the door car itself and providing ribs. However, in recent years, the weight of sashes, hinged doors, etc. has become heavy, and it is not sufficient to suppress the amount of deformation by a method of increasing the number of door cars or a design change of door cars,
Improvements in terms of materials are eagerly desired.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a polyacetal resin door roller effective as a door roller such as a sash or a hinged door.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, it was found that a polyacetal resin roller having a spherulite size of 0.001 to 10 μm is effective.
The present invention has been reached. That is, the present invention is: 1. A polyacetal resin roller having a spherulite size of 0.001 to 10 µm. The polyacetal resin according to the present invention, which is the polyacetal resin door roller according to the above 1 having a heat of fusion of 130 to 150 J / g, means a homopolymer of formaldehyde, a trimer of formaldehyde (trioxane) or a tetramer ( Tetraoxane) and other cyclic oligomers and ethylene oxide, propylene oxide, epichlorohydrin, 1,3-dioxolane, 1,
Terminal stabilization of an oxymethylene-oxyalkylene copolymer containing 0.1 to 20% by weight of an oxyalkylene unit having 2 to 8 carbon atoms, which is produced from cyclic formal such as 4-butanediol, glycol formal or diglycol formal. A polyacetal resin composition obtained by adding a nucleating material or a polyacetal resin having a branched or crosslinked structure to the polyoxymethylene copolymer obtained by the treatment.

The nucleating material is boron nitride, talc, calcium carbonate, silicon carbide, zinc oxide, silicon dioxide, iron oxide, among which boron nitride, talc, silicon carbide and calcium carbonate are preferable. The particle size and the addition amount of these nucleating materials are not particularly limited. On the other hand, a polyacetal resin having a branched or crosslinked structure is a monofunctional or polyfunctional glycidyl ether having at least 1 to 2 epoxy rings in one molecule capable of forming a branch or crosslink, at the time of polymerization of the polyacetal resin. It can be used.

Examples of monofunctional or polyfunctional glycidyl ethers are, for example, ethylene glycol diglycidyl ether, propylene glycol glycidyl ether,
1,4-butanediol diglycidyl ether, hexamethylene glycol diglycidyl ether, resorcinol diglycidyl ether, bisphenol A diglycidyl ether, polyethylene glycol diglycidyl ether, polybutylene glycol diglycidyl ether and the like. The above-mentioned branched or crosslinked polyacetal resin is also effective as a nucleating material, and can be added to the polyacetal resin in the same manner as the nucleating material described above.

The spherulite size described in the present application can be measured by observing a superfoil piece cut out by the cross-section method of the door roller with a polarizing microscope. The polyacetal resin door roller of the present invention has a spherulite size of 0.001 to 10 μm. A polyacetal resin door roller having a spherulite size within the range of 0.001 to 10 μm is preferable because the door roller itself is not deformed after opening and closing when it is used for a door roller such as a sash or hinged door for a long period of time.

The heat of fusion specified in the present invention is generally a value measured by a differential scanning calorimeter (DSC). Specifically, it is defined as the amount of heat (J / g) required for melting the polyacetal resin after the polyacetal resin is charged into the heating furnace of the differential scanning calorimeter and heated at a constant rate. The shape and size of the polyacetal resin door roller referred to in the present invention is not particularly limited. Conventionally designed door rollers, for example door rollers with ribs for the purpose of improving compression deformability and formability, door rollers without reinforcement such as ribs, door rollers insert-molded with metal bearings, or metal shafts A door roller or the like in which a resin bearing portion is insert-molded is also included in the door roller referred to in the present application.

The polyacetal resin door roller of the present invention further comprises an antioxidant, a heat stabilizer, an inorganic or organic colorant, a release agent, which can be added to the polyacetal resin.
It is also possible to use a polyacetal resin added with a surfactant, a lubricant, a reinforcing material such as glass fiber, etc. within a range not impairing the object of the present invention. The method for molding the polyacetal resin door roller of the present invention is not particularly limited,
It can be molded by a molding method that has been used conventionally, and the shape of the mold can be multiple molding using a pin gate mold that has been molded conventionally, or injection molding using a mold for hot runner. It is not specified in particular. Usually, the polyacetal resin can be molded without any problem if it is within the molding condition range. For example, the resin temperature is in the range of 190 ° C to 220 ° C, and the mold temperature is in the range of 40 ° C to 90 ° C.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples. The method for measuring the heat of fusion of the polyacetal resin described in the examples, the method for measuring the compression deformation amount of the door roller after the open / close running test, and the method for observing the crystals of the door roller molded product are shown below. (1) Method of measuring heat of fusion 1 In the cross-sectional direction, use the polyacetal resin door roller shown in Table 1.
An ultrafoil piece having a thickness of 0 μm was cut out, and a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer Co., Ltd.) was used to measure 50 ° C. to 2 ° C.
The measurement was performed by raising the temperature in the range of 00 ° C. at a heating rate of 2.5 ° C./min (first scan). (2) Dimensions of the door roller and molding conditions Using an injection molding machine of 120 tons, diameter 27φ, wall thickness 3
We took 4 mm door rollers and molded them with a mold. The molding conditions at this time are: resin temperature 200 ° C., mold temperature 90 ° C., cooling time 1
It was set to 5 seconds.

(3) Opening / closing running test The load of the hinged door was set to 40 kgf, two cars were installed at each of the two corners of the hinged door, and an opening / closing running test was conducted at a constant speed of 10,000 times / day for 400,000 times. The roundness (deformation amount) of the door roller body after the open / close running test was measured and evaluated by the following method. The environmental temperature during the open / close running test was 60 ° C. (4) Roundness (amount of deformation) of the door roller main body The roundness RA-400 (circularity cylindrical shape measuring instrument) manufactured by Mitutoyo was used to evaluate the roundness difference before and after the 400,000 opening / closing test. (5) Crystal state observation The door roller obtained by injection molding is 10 μm with a microtome.
A superfoil piece having a thickness of 1 was cut out and the spherulite state was observed with a polarizing microscope.

(6) Particle size of nucleating material It was observed by a scanning electron microscope (SEM) and expressed as an average particle size. The abbreviations used in the table are as follows. Polyacetal resin a-1: Tenac 3010 (manufactured by Asahi Kasei Co., Ltd.) a-2: Tenac 4010 (manufactured by Asahi Kasei Co., Ltd.) Nucleating material b-1: Boron nitride average particle size 3 μm b-2: Silicon carbide average particle size 4 μm b-3: talc average particle size 8 μm

[0014]

Examples 1-5 and Comparative Examples 1-2 The polyacetal resin composition shown in Table 1 was molded by an injection molding machine. The obtained door roller was left in a thermostatic chamber at 23 ° C. (humidity: 50%) for 48 hours, and observed with a spherulite size, a heat of fusion and a polarizing microscope.
After that, an opening / closing test was performed. The results are shown in Table 1.

[0015]

[Table 1]

[0016]

The present invention has a heat of fusion of 130 to 150 J.
This is a door roller made of a polyacetal resin consisting of / g of polyacetal resin, which can suppress the compressive deformation of the door roller when it is used for a long period of time, and improves the open / close running performance of the sash and the swing door.

[Brief description of drawings]

[Figure 1] Schematic diagram of a door roller made of polyacetal resin

FIG. 2 is a spherulite photograph by a phase contrast microscope of Example 1 of the present invention.

FIG. 3 is a spherulite photograph by a phase contrast microscope of Comparative Example 1.

[Explanation of symbols]

1. Door car body 2. Bearing part 3. Ribs

Claims (2)

[Claims] 1. A polyacetal resin roller having a spherulite size of 0.001 to 10 μm. 2. The polyacetal resin door roller according to claim 1, which has a heat of fusion of 130 to 150 J / g.