JPH06312429A - Synthetic resin roll - Google Patents

Abstract

PURPOSE:To obtain a light-weight and low-cost synthetic resin roll having an excellent dimensional accuracy by forming the roll of a long cylindrical body in which circumferential and longitudinal thicknesses are substantially uniform and a special shape unit integrally injection molded with the body. CONSTITUTION:A synthetic resin roll is formed of a long cylindrical body 1 in which circumferential and longitudinal thicknesses are substantially uniform and a special shape unit 12 integrally injection molded with the body 1. The unit 12 is formed in a frame unit or other. In the case of manufacturing, molten resin fed from an injection unit of an injection molding machine through a sprue 2 and a runner 3 is charged in a cylinder from a gate. A column 6 for forming an inner surface of a roll (cylindrical body 1 and a special shape unit 12) is assembled in the molds. Further, the molds are formed in an integral structure in which right and left molds (a stationary mold 4 and a movable mold 5) are opened at a center of the roll as a boundary, and recesses for molding outside of the roll are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin roll used as a part for office machines, electric / electronic devices, machines and the like. More specifically, the wall thickness in the circumferential and longitudinal directions is substantially uniform. The present invention relates to a thermotropic liquid crystal resin roll comprising a synthetic resin cylindrical body and a deformed body integrally formed with the cylindrical body by injection molding. The long length here specifically means the length (L) and the diameter (D) corresponding to the cross-sectional area.
The ratio (L / D) (hereinafter referred to as equivalent diameter) means 2 or more, and the equivalent diameter (D) is a circular outer shape in the case of a cylindrical object having a circular cross section. Yes, and in the case of a cylindrical object whose cross section has a shape other than a circle such as a triangle or a square, it is expressed by the following mathematical formula 1.

[0002]

[Equation 1]

[0003]

2. Description of the Related Art Rolls used as parts for office machines, electric / electronic devices, machines, etc. are required to have strength and dimensional accuracy, and are mainly made of metal at present. In actual use, deformed bodies such as rotary shafts, gears, and flanges for guides are often attached to the cylindrical body in order to exert the function as a roll. This is not rational since the two are integrated by welding, bolting or cutting and polishing the flanged product, etc.

Further, in recent years, there has been an increasing demand for weight reduction in the use as a mechanical part as described above, and development of a lightweight roll has been desired.

Although it is desirable to use a synthetic resin in order to manufacture an inexpensive and lightweight roll, an extrusion molding method is generally used to mold a long tubular material having an L / D of 2 or more. . However, it is difficult to obtain a cylindrical product with high dimensional accuracy by this molding method, and it is not suitable for use in applications such as rolls.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a synthetic resin roll which is lightweight, has good dimensional accuracy, and is inexpensive.

[0007]

The present inventors have reached the present invention as a result of various examinations in view of the above-mentioned situation in a synthetic resin roll.

That is, according to the present invention, a synthetic resin roll comprising a long cylindrical body having a substantially uniform thickness in the circumferential direction and the longitudinal direction and a deformed body integrally formed with the cylindrical body by injection molding. It is in.

The cylindrical body of the synthetic resin roll of the present invention is long. Specifically, it is necessary that the L / D is 2 or more and the thicknesses in the circumferential direction and the longitudinal direction are substantially uniform. L
If / D is less than 2, it does not function as a roll,
If the wall thickness is not uniform, the tubular body may be warped or distorted, which causes inconvenience. Therefore, the term “substantially” as used herein means being uniform to the extent that such deformation does not occur.

In the present invention, the shape of the tubular body is generally a cross section, that is, a cylinder, but it may be a rectangular tube having a triangular or square cross section or the like. The size is not particularly limited, and the length (L) is as small as a few centimeters and is 1
Even large ones exceeding meters are possible. The thickness is also 1
It can be as thin as a millimeter or less and as thick as a few centimeters. The side surface of the tubular body may be open on both sides or closed on one side.

An injection molding method is adopted for producing the synthetic resin roll of the present invention. There are various molding methods of synthetic resin such as extrusion molding, hollow molding, injection molding, compression molding, etc., but in order to integrally mold with a profile and obtain a roll with good dimensional accuracy, a method other than injection molding is used. Is not appropriate.

The injection molding machine used in the present invention is also not particularly limited. Screw in-line type, pre-plastic type,
Any type of molding machine such as a horizontal type, a rigid type, or a type having a compression mechanism can be used.

In the present invention, the deformed body integrally formed with the tubular body has various shapes, and typical examples thereof include a gear body, a collar body and a shaft body.

When using this roll, the gear body 11 is
It serves to transmit power and is usually attached to the end of the tubular body 1 as shown in FIG.

One or a plurality of collar bodies 12 are attached to the end portion or body portion of the tubular body 1, and when this roll is used as a roll for OA equipment, it can be used for paper, film, sheet, belt, etc. It works as a guide. The shape is generally circular as shown in FIG. 2, but may be square or elliptical.

As shown in FIG. 3, the shaft-shaped body 13 is a cylindrical body 1.
It is attached to the end of the roll and is usually used as a drive shaft when the roll is rotated. Since it is manufactured by injection molding, unlike the former two, it is impossible to integrally attach a plurality of the different shapes. If you want to attach a shaft to both ends,
One shaft is separately molded and attached by adhesion, welding, or mechanical joining means.

The synthetic resin used in the present invention is not particularly limited as long as it is a thermoplastic synthetic resin. Polyolefin resin such as polyethylene, polypropylene, polybutene, polystyrene resin, polyvinyl chloride resin, nylon 6
And aromatic polyamide resins such as nylon 66 and nylon 66, aromatic polyamide resins such as polyphthalamide, polycarbonate resins, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyoxymethylene resins, polyphenylene ether resins, polyurethane -Based resin, polysulfone-based resin, polyether sulfone-based resin, polyphenylene sulfide-based resin,
Examples thereof include polyketone-based resins, thermotropic liquid crystal polyester resins, polyarylate-based resins, polyimide-based resins, polyamide-imide-based resins, and fluorine-based resins. Of these, it is easy to develop strength and dimensional accuracy as a roll, and a thermotropic liquid crystal resin having high fluidity, particularly a thermotropic liquid crystal polyester resin, is suitable for molding a long tubular product. is there.

The thermotropic liquid crystal resin referred to here is
It is a thermoplastic, meltable polymer that exhibits optical anisotropy when melted. As described above, the polymer exhibiting optical anisotropy when melted has a property that the polymer molecular chains have a regular parallel arrangement in the melted state. The properties of the optically anisotropic molten phase can be confirmed by a usual polarization inspection method using a crossed polarizer.

For example, liquid crystalline polyester, liquid crystalline polyester imide and the like, specifically (all) aromatic polyester, polyester amide, polyester carbonate and the like can be mentioned. The thermotropic liquid crystal polyester resin is included in the category of polyester as long as it has a plurality of ester bonds in the molecule. More preferred polyester is
It is an aromatic polyester.

In the thermotropic liquid crystal polyester resin used in the present invention, a part of one polymer chain is composed of a polymer segment forming an anisotropic melt phase, and the rest is an anisotropic melt phase. Also included are polymers composed of segments of polymer that do not form. Also,
A composite of a plurality of thermotropic liquid crystal polyester resins is also included.

As typical examples of the monomer constituting the thermotropic liquid crystal polyester resin, (a) at least one aromatic dicarboxylic acid, (b) at least one aromatic hydroxycarboxylic acid compound, and (c) aromatic At least one kind of diol compound, (d) at least one kind of (d ₁ ) aromatic dithiol, (d ₂ ) aromatic thiophenol, (d ₃ ) aromatic thiolcarboxylic acid compound, (e) aromatic At least one kind of a hydroxyamine and an aromatic diamine compound may be used.

Although these may be configured independently,
Many are (a) and (c), (a) and (d), (a),
(B) and (c), (a), (b) and (e), or (a), (b), (c) and (e), etc. are combined and configured.

As the above-mentioned (a) aromatic dicarboxylic acid type compound, terephthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-triphenyldicarboxylic acid, 2,6-
Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenylether-4,4'-dicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenoxybutane-4,
4'-dicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid, isophthalic acid, diphenylether-3,
3'-dicarboxylic acid, diphenoxyethane-3,3'-
Aromatic dicarboxylic acids such as dicarboxylic acid, diphenylethane-3,3'-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid or chloroterephthalic acid, dichloroterephthalic acid, bromoterephthalic acid, methylterephthalic acid,
Examples thereof include alkyl, alkoxy or halogen substitution products of the above aromatic dicarboxylic acids such as dimethyl terephthalic acid, ethyl terephthalic acid, methoxy terephthalic acid and ethoxy terephthalic acid.

Examples of the aromatic hydroxycarboxylic acid compound (b) include aromatic hydroxy such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and 6-hydroxy-1-naphthoic acid. Carboxylic acid or 3-methyl-4-hydroxybenzoic acid, 3,5
-Dimethyl-4-hydroxybenzoic acid, 2,6-dimethyl-4-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3,5-dimethoxy-4-hydroxybenzoic acid, 6-hydroxy-5-methyl -2-naphthoic acid, 6-hydroxy-5-methoxy-2-naphthoic acid,
2-chloro-4-hydroxybenzoic acid, 3-chloro-4
-Hydroxybenzoic acid, 2,3-dichloro-4-hydroxybenzoic acid, 3,5-dichloro-4-hydroxybenzoic acid, 2,5-dichloro-4-hydroxybenzoic acid, 3
-Bromo-4-hydroxybenzoic acid, 6-hydroxy-
Alkyl, alkoxy or halogen substitution of aromatic hydroxycarboxylic acid such as 5-chloro-2-naphthoic acid, 6-hydroxy-7-chloro-2-naphthoic acid, 6-hydroxy-5,7-dichloro-2-naphthoic acid The body.

As the aromatic diol (c), 4,4 '
-Dihydroxydiphenyl, 3,3'-dihydroxydiphenyl, 4,4'-dihydroxytriphenyl, hydroquinone, resorcin, 2,6-naphthalenediol, 4,4'-dihydroxydiphenyl ether, bis (4-hydroxyphenoxy) ethane, 3 , 3'-Dihydroxydiphenyl ether, 1,6-naphthalenediole, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane and other aromatic diols or chlorohydroquinone Alkyl, alkoxy or halogen substitution products of aromatic diols such as methyl hydroquinone, t-butyl hydroquinone, phenyl hydroquinone, methoxy hydroquinone, phenoxy hydroquinone, 4-chlororesorcinol and 4-methylresorcinol. That.

Examples of (d ₁ ) aromatic dithiol include benzene-1,4-dithiol, benzene-1,3-dithiol, 2,6-naphthalene-dithiol and 2,7-naphthalene-dithio. -Ru and the like.

Examples of the (d ₂ ) aromatic thiophenol include:
4-mercaptophenol, 3-mercaptophenol
And 6-mercaptophenol and the like.

Examples of (d ₃ ) aromatic thiol carboxylic acid include 4-mercaptobenzoic acid, 3-mercaptobenzoic acid, 6-mercapto-2-naphthoic acid and 7-mercapto-2-naphthoic acid.

(E) Aromatic hydroxyamine and aromatic diamine compounds include 4-aminophenol and N-
Methyl-4-aminophenol, 1,4-phenylenediamine, N-methyl-1,4-phenylenediamine,
N, N'-dimethyl-1,4-phenylenediamine, 3
-Aminophenol, 3-methyl-4-aminophen-
2-chloro-4-aminophenol, 4-amino-
1-naphthol, 4-amino-4'-hydroxydiphenyl, 4-amino-4'-hydroxydiphenylether, 4-amino-4'-hydroxydiphenylmethane,
4-amino-4'-hydroxydiphenyl sulfide,
4,4'-diaminophenyl sulfide (thiodianiline), 4,4 'diaminodiphenyl sulfone, 2,5-
Diaminotoluene, 4,4'-ethylenedianiline,
4,4'-diaminodiphenoxyethane, 4,4'-diaminodiphenylmethane (methylenedianiline), 4,
4'-diaminodiphenyl ether (oxydianiline) and the like can be mentioned.

The thermotropic liquid crystal polyester resin used in the present invention can be produced from the above-mentioned monomers by various ester forming methods such as a melt acidolysis method and a slurry polymerization method.

As for the molecular weight, that of the thermotropic liquid crystal polyester resin suitable for use in the present invention is about 2
000-200000, preferably about 4000-100
It is 000. The molecular weight can be measured, for example, by measuring the end groups of a compressed film by infrared spectroscopy. Alternatively, GPC, which is a general measurement method involving solution formation, can be used.

Among the thermotropic liquid crystal polyester resins obtained from these monomers, aromatic polyesters which are (co) polymers containing the monomer unit represented by the following general formula (1) as an essential component are preferable. The monomer unit preferably contains about 30 mol% or more. More preferably, it contains about 50 mol% or more.

[0033]

[Chemical 1]

A particularly preferred aromatic polyester of the present invention is a copolyester represented by the following formula (2) having repeating units each having a structure derived from three compounds of p-hydroxybenzoic acid, phthalic acid and biphenol. is there. The repeating unit of the structure derived from the biphenol of the copolyester represented by the following formula (2) is
It may also be a copolyester in which some or all of it is substituted with repeating units derived from dihydroxybenzene. It is a copolyester represented by the following formula (3) having repeating units each having a structure derived from two compounds of p-hydroxybenzoic acid and hydroxynaphthalenecarboxylic acid.

[0035]

[Chemical 2]

[0036]

[Chemical 3]

The thermotropic liquid crystal polyester resin used in the present invention may be used alone, or two or more kinds thereof may be mixed and used.

Two or more kinds of these synthetic resins can be used or a mixture of other polymers such as rubber can be used.
At this time, it is preferable to use a compatibilizing agent in order to improve the compatibility of each component. Further, these synthetic resins can be used after being chemically modified.

Various additives can be added to the above synthetic resin depending on the purpose. This includes inorganic and organic fillers (glass fiber, carbon fiber, talc, mica, calcium carbonate, clay, calcium sulfate, magnesium hydroxide,
Silica, alumina, barium sulfate, titanium oxide, zinc oxide, iron oxide, ferrite, molybdenum sulfide, graphite, wood powder, various whiskers, metal powder, glassy carbon, etc., various stabilizers (antioxidant, ultraviolet absorber, Light stabilizers, metal deactivators, etc.), pigments, dyes, plasticizers, oils, lubricants, nucleating agents, antistatic agents, flame retardants and the like.

Particularly, the content of the inorganic filler is 90% by weight or less, preferably 80% by weight or less and 1% by weight or more.
The injection-molded article of the present invention formed by using a thermotropic liquid crystal resin by blending an inorganic filler has a good surface condition and is preferable. In addition, the one containing the above-mentioned inorganic filler is suitable as a material for the roll of the present invention, since rigidity, strength, heat resistance, etc. are improved and dimensional accuracy is improved.

Further, since the roll of the present invention is used with a gear body, a collar-shaped body, a shaft-shaped body, etc. attached thereto, it often comes into contact with and slides on other members, so that it can be used as a material. You may be required to take action. In this case, a slidability improving material, for example, the above-mentioned filler, particularly carbon fiber, talc, calcium sulfate, molybdenum sulfide, etc., is added to the synthetic resin, and another synthetic resin, for example, a fluorine-based resin or the like is added. It is preferable to use one having improved sliding characteristics. The blending amount of these is the same as the blending amount of the inorganic filler.

When the present invention is carried out, since the shape is special and complicated, it is necessary to devise the structure of the mold. For example, when molding a roll with a gear body, a mold having a slide mechanism is required when the mold is opened. Further, in order to mold the tubular body with higher dimensional accuracy, a ring slidable in the cavity forming the tubular body inside the mold is fitted to the column body forming the inside of the tubular body. It is effective to mold while moving this ring by the molten resin introduced. The ring 7 is fitted in the cylinder 6 to such an extent that the molten resin does not leak from the gap where it is fitted.

FIG. 4 is a schematic sectional view showing the injection molding method of this synthetic resin roll. As shown in FIG. 4, the sprue 2 and the runner 3 are connected to the injection unit of the injection molding machine.
The molten resin that has been sent through through flows from the lower part of the cylinder through the gate 7 and is filled upward. A cylinder 6 for forming the inner surface of the roll (cylindrical body 1 and collar body 12) is incorporated in the mold.

The mold generally has a pair of structures (a fixed mold 4 and a movable mold 5, rarely an intermediate plate may be inserted between them) which opens left and right with the center of the roll as a boundary.
Each is formed with a recess to form the outside of the roll. However, in this case, traces (parting lines) of the mating surfaces of the two molds may remain on the surface of the molded product and spoil the appearance. In order to avoid this, the auxiliary mold (cylindrical structure) for forming the outside of the roll is incorporated into the fixed mold 4 and the movable mold 5, and after injection, the auxiliary mold is released together with the auxiliary mold. A method of removing the cylinder 6 for forming the inside of the mold and the roll is adopted.

The cylinder 6 may be integrally attached to the fixed mold 4 or the movable mold 5, but a mechanism for taking out the molded product must be provided in association with the mold, which complicates the structure. In addition, it takes time to remove the mold, which is not preferable. Therefore,
It is preferable that the column 6 has a structure that can be detached from the mold body. In this case, the roll is demolded together with the cylinder 6 after molding, and the cylinder 6 is separately removed, which facilitates the removal operation.

Further, a ring (not shown) slidable in the cavity forming the roll inside the molding die is fitted into the cylinder 6 forming the inside of the roll, and the molten resin introduced. To move the ring while moving. Since this ring has the effect of holding the cylinder 6 in the mold while the molten resin is being introduced, the cylinder does not shift and a molded product with good dimensional accuracy can be obtained. As this ring, a ring corresponding to the cross-sectional shape of the tubular body is appropriately used.

The fitting position of the ring is not particularly limited,
In order to obtain a molded product with better dimensional accuracy, it is preferable to be as close to the gate as possible. The cylinder 6 can be fitted manually, but it can also be automated using a robot.

It is preferable that the mating ring has a little resistance to movement during molding so that the surface of the molded product after molding becomes smooth. Especially when a thermotropic liquid crystal polyester resin is used as the synthetic resin, this tendency is particularly large. If the ring moves easily, flow patterns will appear on the surface. Therefore, if there is a little resistance to the movement of the ring, the ring will be molded while being filled with the resin and the surface will be smooth. This requires that the ring be in intimate contact with the cylinder and / or the mold (fixed and mobile).

The material of the ring is generally resin or metal. As the resin ring, for example, a tubular body (pipe) in the present invention is cut to form a ring, which has a considerable resistance and is preferable. This is the case where the pipe removed from the mold after molding can fit into the cylinder 6. If the formed tubular body contracts or expands, it cannot be fitted into the column 6 and cannot be used. Since the thermotropic liquid crystal polyester resin has a characteristic that the molding shrinkage is small and a molded body can be formed exactly according to the dimension of the mold, the tubular body made of the thermotropic liquid crystal polyester resin is cut,
It is preferably a ring.

On the other hand, the metal ring may be made of the same material as that of the mold body, but it may damage the mold.
It is preferable to use a metal whose hardness is lower than that of the mold. Suitable materials include gun metal, brass, copper, aluminum, duralumin and the like.

To fit the metal ring in close contact with the cylinder 6, a groove is provided in the longitudinal direction of the ring. The smaller the number of grooves, the easier it is to close. To close the metal ring, a tightening circular spring is fitted in a groove formed in the lateral direction of the ring. This may be done by fitting a rubber band. Since this circular spring is fitted in the groove, it does not interfere with the movement of the ring.

When such a tightening circular spring is used, since the groove is provided in the ring in the vertical direction, the ring is tightened and the ring diameter is reduced. As a result, the ring is a cylinder 6.
The ring moves with resistance while closely fitting.

On the contrary, instead of the tightening circular spring, an extending circular spring may be used. When this spring is used, since the groove is provided in the ring in the vertical direction, the ring extends and the ring diameter increases. As a result, the ring is pressed against the fixed die 4 and the movable die 5, and the ring moves while having resistance.

Further, the ring for forming a roll having a collar-shaped body is required to have a width larger than that of the flange portion. If the width of the ring is smaller than the width of the collar, when the ring is pushed up by the resin and rises, the ring is likely to move in the collar, and as a result, a cylindrical object with excellent dimensional accuracy may not be obtained. There is.

In the case of thermotropic liquid crystal resin, particularly thermotropic liquid crystal polyester resin, the injection molding conditions are, for example, a resin temperature of 200 to 420 ° C. and a mold temperature of 6.
0 to 170 ° C., more preferably 60 to 130 ° C., injection pressure 1 to 200 kg / cm ² , injection speed 5 to 500 mm /
It can be appropriately selected from the range of sec.

After the injection molding, the mold is moved to remove from the mold together with the cylinder 6, the molded product is taken out, and the cylinder 6 is extracted to obtain a cylindrical product. In the case of a thermotropic liquid crystal resin, particularly a thermotropic liquid crystal polyester resin, the dimensional accuracy is good, so that the column 6 can be easily pulled out.

The thickness, diameter, and length of the long tubular injection-molded product of the present invention,
Specific dimensions such as length are not particularly limited as long as they are long cylindrical objects depending on the shape of the mold that can be manufactured, but in the case of thermotropic liquid crystal resin, particularly thermotropic liquid crystal polyester resin, for example, the thickness Is 0.
5 mm or more, preferably 1 mm or more and 10 cm or less, and the equivalent diameter is 5 mm or more, preferably 8 mm or more, 10
The length is 00 mm or less and the length is 10 mm or more, preferably 50 mm or more and 10 m or less.

[0058]

EXAMPLES The present invention will be specifically described below based on Examples and the like.

Example 1 70 parts by weight of polybutylene terephthalate (produced by Kuraray Co., Ltd., trade name Hauser R1300) was used as a synthetic resin, and 30 parts by weight of glass fiber was added thereto, and a mold thickness dimension of 350 mm as shown in FIG. Injection molding was performed using a metal ring by the mold of. After the injection molding, the mold was moved, the mold was removed together with the cylinder 6, the molded product was taken out, and the cylinder 6 was extracted to obtain a cylindrical product.

As a result, the length is 107 mm and the outer diameter is 20 m.
m, a wall thickness of 2 mm, and a flange thickness of 2 mm (three flanges) were obtained, and a synthetic resin roll with a collar body was obtained. The maximum thickness difference of this injection-molded product was 0.2 mm.

An IS-80 injection molding machine (clamping stroke 460 mm) manufactured by Toshiba Machine Co., Ltd. was used as a molding machine, and the molding temperature was 250 ° C., the injection speed was 100 mm / sec, and the mold temperature was 60.
Performed at ° C. The ring size was 20 mm in outer diameter, 16 mm in inner diameter, and 10 mm in height, and the ring material was gun metal (alloy of 90% by weight of copper and 10% by weight of tin).

Example 2 As a synthetic resin, a thermotropic liquid crystal polyester resin (phthalic acid / isophthalic acid / 4-hydroxybenzoic acid /
A thermotropic liquid crystal copolyester resin having repeating units each derived from 4,4-dihydroxydiphenyl, each having a molar ratio of 0.75 / 0.
It is 25/3/1. This is 34 when the optical anisotropy was observed using a polarization microscope equipped with a hot stage.
It exhibits optical anisotropy in a molten state at 0 ° C. or higher, and at the time of injection molding, a resin containing 30% by weight of glass fiber was used), and a mold thickness dimension 3 as shown in FIG.
Injection molding was performed using a metal ring with a 50 mm die. After the injection molding, the mold was moved, the mold was removed together with the cylinder 6, the molded product was taken out, and the cylinder 6 was extracted to obtain a cylindrical product.

As a result, the length is 300 mm and the outer diameter is 16 m.
m, a wall thickness of 2 mm and a flange thickness of 2 mm (three flanges), a synthetic resin roll with a collar body was obtained. The maximum thickness difference of this injection-molded product was 0.1 mm.

An IS-80 injection molding machine (clamping stroke 460 mm) manufactured by Toshiba Machine Co., Ltd. is used as a molding machine, and the molding temperature is 350 ° C., the injection speed is 50 mm / sec, and the mold temperature is 80 ° C.
I did it in. Also, the ring dimensions are 16 mm outer diameter and 1 inner diameter.
The ring material was 2 mm, the height was 20 mm, and the ring material was gunmetal (an alloy of 90% by weight of copper and 10% by weight of tin).

Example 3 The thermotropic liquid crystal polyester resin used in Example 2 was used as a synthetic resin, and injection molding was performed using a metal ring with a mold having a mold thickness dimension of 350 mm. After the injection molding, the mold was moved, the mold was removed together with the cylinder 6, the molded product was taken out, and the cylinder 6 was extracted to obtain a cylindrical product.

As a result, the length is 300 mm and the outer diameter is 16 m.
A synthetic resin roll with a shaft-shaped body of m, wall thickness 2 mm, and shaft (diameter 10 mm) was obtained. The maximum thickness difference of this injection-molded product was 0.1 mm.

An IS-80 injection molding machine (clamping stroke 460 mm) manufactured by Toshiba Machine Co., Ltd. was used as a molding machine, and the molding temperature was 350 ° C., the injection speed was 50 mm / sec, and the mold temperature was 80 ° C.
I did it in. Also, the ring dimensions are 16 mm outer diameter and 1 inner diameter.
The ring material was 2 mm, the height was 20 mm, and the ring material was gunmetal (an alloy of 90% by weight of copper and 10% by weight of tin).

[0068]

EFFECTS OF THE INVENTION The roll of the present invention is formed of a relatively long cylindrical body made of synthetic resin and a deformed body such as a gear body, a collar body, and a shaft body integrally formed, and therefore is lightweight and has a cylindrical shape. The strength between the shaped body and the deformed body is high and it is inexpensive. Moreover, since the product is manufactured by injection molding, it is possible to efficiently mold a product having excellent dimensional accuracy. In particular, if a thermotropic liquid crystal polyester resin or a synthetic resin mixed with an inorganic filler is used, the strength and dimensional accuracy are further improved, and it is suitable as a roll for OA equipment and electric equipment. The roll of the present invention having various characteristics as described above can be used as a component of precision machines, electric products, etc. in addition to OA equipment and electronic equipment.

[Brief description of drawings]

FIG. 1 is a perspective view of a synthetic resin roll having a gear body according to the present invention.

FIG. 2 is a perspective view of a synthetic resin roll with a collar body according to the present invention.

FIG. 3 is a perspective view of a synthetic resin roll with a shaft-shaped body of the present invention.

FIG. 4 is a schematic sectional view showing an injection molding method of a synthetic resin roll of the present invention.

[Explanation of symbols]

1: Cylindrical body, 11: Gear body, 12: Collar body, 13: Shaft body, 2: Sprue, 3: Runner, 4: Fixed type, 5: Movable type, 6: Cylinder, 7: Gate.

Claims (6)

[Claims] 1. A synthetic resin roll comprising a long cylindrical body having a substantially uniform thickness in the circumferential direction and the longitudinal direction, and a deformed body integrally formed with the cylindrical body by injection molding. 2. The synthetic resin roll according to claim 1, wherein the deformed body is a gear body. 3. The synthetic resin roll according to claim 1, wherein the profile is a brim. 4. The synthetic resin roll according to claim 1, wherein the deformed body is a shaft-shaped body. 5. The synthetic resin roll according to claim 1, wherein the synthetic resin is a thermotropic liquid crystal resin. 6. The synthetic resin roll according to claim 1, wherein the synthetic resin contains an inorganic filler.