JPH02218733A - Platen roll - Google Patents

Abstract

PURPOSE:To obtain a platen roll which can be used over a wide range of applications such as parts of copying machines, because of its excellent printing properties, durability and so on by forming a composition adding glass fibers, inorganic fillers, when needed, a variety of additives to a specific phenolic resin. CONSTITUTION:As a phenolic resin, is used a rubber-modified phenolic resin which has been prepared by adding a rubber containing epoxy groups in its molecules to a phenolic resin and melting them. 100 pts.wt. of the phenolic resin are combined with 40 to 200 pts.wt. of glass fibers, inorganic fillers such as magnesia or the like, when needed, a lubricant, a plasticizer, an electro- conductivity-endowing agent and other additives, kneaded and crushed to give a composition. The composition is compression-molded or extrusion-molded to give the subject platen roll. The use of a rubber-modified novolak phenolic resin as a phenolic resin is combined with addition of a curing agent such as hexamethylenetetramine.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a roll used for printing and feeding paper for output devices in computers, etc., which has improved printing characteristics, durability, noise reduction, and formability. This relates to platen rolls.

[Prior Art] Conventionally, print type printing methods have often been used in output devices such as computers. In recent years, as printing speeds have increased, dot type platen rolls used in output devices have become more mainstream than type type. Because the dot type is subject to a greater impact than the type, the roll surface often suffers from dents.

Usually, the platen roll for printing has a metal shaft core, e.g.
Stainless steel shaft, brass shaft, aluminum shaft, usually on a round bar with a diameter of 8 to 25IIIm, made of natural rubber, urethane rubber, styrene butadiene rubber, nitrile rubber, ethylene propylene rubber, synthetic rubber such as chloroprene rubber, or two types thereof. Vulcanized rubber of the above blend rubber, thermoplastic polyester urethane rubber, polyether elastomer, thermoplastic elastomer based on ethylene-propylene copolymer, copolymer polyamide thermoplastic elastomer, styrene-butadiene It is coated with a thermoplastic elastomer such as block cobolimer and used.

When actual machine tests are conducted using rolls coated with these rubbers and thermoplastic elastomers, natural rubber and urethane rubber have large impact resilience and cause printing delays.

Synthetic rubbers and thermoplastic elastomers have the disadvantage that the concavity phenomenon occurs relatively quickly, and their moldability is poor.

Like the printing platen roll, the paper feeding platen roll has a metal shaft inserted through the center of the roll in the axial direction.
A circular layer of natural rubber or synthetic rubber is formed on the outer peripheral surface of the shaft core.

These paper feeding platen rolls had the disadvantage that paper pieces adhered to the roll during use, resulting in gradual deterioration of paper feeding performance.

[Problems to be Solved by the Present Invention] The purpose of the present invention was to provide a platen roll having excellent printing characteristics, durability, noise reduction, and formability. It's about doing.

[Means for Solving the Problems] As a result of various studies to solve the above-mentioned problems, the present inventors have formulated a rubber-modified phenolic resin having an epoxy group in the molecule, glass fiber, and an inorganic filler. It was discovered that a platen roll with excellent printing characteristics, noise reduction, and moldability can be obtained by molding the composition, leading to the present invention.

That is, the present invention provides a platen roll formed by molding a composition containing a phenolic resin, glass fiber and/or an 8I-free filler, and various additives as needed in desired amounts. V! is a composition formed by crosslinking a phenolic resin with a rubber-modified phenolic resin having an epoxy group in the molecule. It is a platen roll marked @.

and a platen roll, characterized in that the coating layer of the metal shaft or metal pipe is molded with the above composition.

The rubber-modified phenolic resin having an epoxy group in the molecule used in the present invention can be obtained, for example, by the method disclosed in JP-A-55-123643.

That is, a rubber having an epoxy group in the molecule is added to a phenol resin, and when the rubber is in a latex state or a solution state, after dehydration or solvent removal, the temperature is 100°C.
It can be obtained by melting and mixing at a temperature above.

The phenolic resin that can be used in the present invention may be a novolac type resin or a resol type resin obtained using an acid or an alkali as a catalyst, or a phenolic resin obtained by using a divalent metal salt.
A high ortho type (novolak with a large amount of ortho bonds) obtained by reacting with H5 to H7 may also be used.

Rubbers having epoxy groups in the molecule include synthetic rubbers such as acrylonitrile butadiene copolymers, styrene butadiene copolymers, and acrylic rubbers having epoxy groups in the molecule. The epoxy group can be easily incorporated into the rubber molecule by adding glycidyl methacrylate or a compound containing an epoxy group and a copolymerizable unsaturated bond in the molecule to the above synthetic rubber component and copolymerizing it. Can be introduced.

In addition, the epoxy group content is not particularly limited, but in order to maximize the effects of the present invention, it is usually good to have an epoxy equivalent of about 1,000 to 30,000 (the above range is glycidyl equivalent). When using methacrylate as a raw material, it corresponds to 0.5 to 15% by weight.

In addition, epoxy equivalent is equivalent per one epoxy group (
g/eqiv), which is the average molecular weight divided by the number of epoxy groups per molecule.

The epoxy-containing rubber is used as a solid, in a latex state, or in a solution state, in an amount of 3 to 40 parts by weight of rubber having an epoxy group in the molecule based on 100 parts by weight of the phenol resin in terms of solid content. If it is less than 3 parts by weight, it will have little effect on printing characteristics and noise reduction. Moreover, if it exceeds 40 parts by weight, moldability will deteriorate. Preferably it is 5 to 25 parts by weight.

The rubber containing an epoxy group in its molecule is melt-blended at a temperature of 100°C or more and 250°C or less after being added to the phenol resin.

In addition, when using rubber containing epoxy groups in the molecule in a Latinx state or in a solution state, it is necessary to dehydrate or remove solvent and then heat it at a predetermined temperature, usually 100°C.
If the temperature is lower than 250 degrees, it is difficult to melt and mix, and if the temperature exceeds 250 degrees, thermal decomposition of the rubber containing an epoxy group in the molecule may occur, which is not preferable.

There is no particular limit to the melt mixing time, but it is usually 3 minutes to 1 minute.
80 minutes is preferable; in other words, if it is less than 3 minutes, the melting and mixing may become incomplete, and conversely, if it exceeds 180 minutes, the effect of the present invention will not change even if it is mixed and melted for a long time.
Less than a minute is sufficient.

Hexamethylenetetramine is usually used as a curing agent for adding the above-mentioned epoxy group to the rubber-modified phenolic resin that exists in the molecule. In this case, hexamethylenetetramine is used in an amount of 8 to 20 parts by weight, preferably 12 to 20 parts by weight, based on 100 parts by weight of the /borac type phenolic resin.
It is used in a range of 15 parts by weight. If it is less than 8 parts by weight, it will be difficult to obtain a satisfactory molded product with excellent printing characteristics, and if it exceeds 20 parts by weight, the noise reduction effect and moldability will deteriorate.

On the other hand, when a rubber-modified resol type phenolic resin having an epoxy group in its molecule is used alone or in combination, there is no need to add a curing agent.

The glass fiber is used in an amount of 40 to 200 parts by weight, preferably 60 to 180 parts by weight, based on 100 parts by weight of the phenolic resin. If it is less than 40 parts by weight, sufficient mechanical strength cannot be obtained, and if it exceeds 200 parts by weight, extrusion moldability will deteriorate.

Other additives include lubricants, colorants, plasticizers, fillers, flame retardants, conductivity imparting agents, and the like.

The lubricant is not particularly limited, but higher fatty acids such as stearic acid and balmitic acid, alkaline earth metal salts (calcium salts, magnesium salts) of higher fatty acids, montanic acid wax, and amides of higher fatty acids can be used. The lubricant may be added by mixing with the resin and others, or may be added after adjusting the composition depending on the case.

Colorants include spirit black, molybdenum red,
Phthalocyan blue, phthalocyan green, Hanzaiero, etc. can be used.

As plasticizers, furfural, alkylphenol,
tricresyl phosphate, polyethylene glycol,
Dibutyl phthalate, P-tol jl.

Commonly used agents such as sulfamide are effective.

Fillers include, but are not limited to, inorganic materials such as magnesia, basic magnesium silicate, magnesium carbonate, magnesium hydroxide, calcium carbonate, kaolin, clay, celite, and acid clay, ceramic fibers, and Hedmann fibers. , rock wool, carbon fiber, etc. can be used.

Examples of flame retardants include antimony oxide and tris(2°3-dibromopropyl) phosphate.

Examples of conductivity imparting agents include carbon black, graphite, and ferric oxide.

In the present invention, in order to obtain the desired platen roll,
Rubber-modified novolac type phenolic resin containing the epoxy group in the molecule, hexamethylenetetramine as a curing agent, or glass fiber in resol type phenolic resin,
A composition is obtained by adding an inorganic filler, a colorant, a plasticizer, a flame retardant, and a conductivity imparting agent as necessary, and kneading and pulverizing the mixture.

All kneading and pulverization can be carried out by known methods. That is, a hot roll, a co-kneader, etc. can be used for pulverization, and a subido mill, a power mill, etc. can be used.

A platen roll can be obtained by molding the resulting composition into a pipe shape by compression molding, transfer molding, extrusion molding, etc., but the composition is particularly effective when used in extrusion molding.

When used as a coating layer for a metal shaft or metal pipe, a pipe with an inner diameter that matches the outer diameter of the metal shaft or metal pipe is extruded, and after forming, the metal shaft or metal pipe is press-fitted and rolled onto a platen roll. is obtained.

[Example] The present invention will be explained below with reference to Examples.

Synthesis examples of a rubber-modified phenolic resin having an epoxy group in its molecule and a rubber-modified phenol resin not containing an epoxy group in its molecule, which are used in the present invention, are shown below.

Synthesis Example 1 Rubber-modified phenolic resin (A) 62 parts by weight of butadiene, 85 parts by weight of acrylonitrile,
At a temperature of 30°C in an autoclave with a composition of 3.0 parts by weight of glycidyl methacrylate, 1.0 parts by weight of dodecyl mercaptan, 0.5 parts by weight of potassium persulfate, 5 parts by weight of an anionic surfactant, and 200 parts by weight of water. Polymerization was carried out for 20 hours to obtain a rubber having epoxy groups in the molecule. The solid content in the rubber latex was 30% by weight, and the epoxy equivalent of the rubber having an epoxy group in the molecule was 4900 after vacuum drying at a temperature of 50° C. or lower.

Add 33 parts by weight of the above rubber to Novolac #2 manufactured by Mitsui Toatsu Chemical Co., Ltd.
After adding 100 parts by weight of 000 (softening point 92 to 98°C) and removing distilled water from the system by vacuum drying, 1
The mixtures were melted and mixed at 60°C for 60 minutes with stirring to obtain a rubber-modified phenol resin (A).

Synthesis Example 2 Rubber-modified phenolic resin, (B) 67 parts by weight of butyl alkylate, 30 parts by weight of acrylonitrile
(parts by weight, 3.0 parts by weight of glycidylnucuacrylate, 100 parts by weight of ethyl acetate, azobis isoptiloni) IJ
After polymerizing for 3 hours under normal pressure and refluxing ethyl acetate at a composition ratio of 1.0 parts by weight, 1.0 parts by weight of azobisisobutyronitrile was added, and then 1.0 parts by weight of azobisisobutyronitrile was added, By polymerizing for a period of time, a rubber having epoxy groups in the molecule was obtained. The solid content in the rubber latex is 49% by weight, and after solvent removal, the epoxy equivalent of the epoxy-containing rubber is 49% by weight.
It was 00.

Add Novolac #2000.10 to 30 parts by weight of the above rubber.
After adding 0 parts by weight and removing distilled water from the system by vacuum drying, the mixture was melt-mixed at 160°C for 60 minutes with stirring to obtain a rubber-modified phenolic resin (B).

Synthesis Example 3 Rubber-modified phenolic resin (C) 64 parts by weight of butyl alkylate, 30 parts by weight of acrylonitrile
Parts by weight, 6.0 parts by weight of glycidyl acrylate, 100 parts by weight of ethyl acetate, 1.0 parts by weight of azobisisobutyronitrile
3 parts by weight under normal pressure and refluxing ethyl acetate.
After polymerization for a period of time, unreacted monomers and solvent were removed to obtain a rubber having epoxy groups in the molecule. The epoxy equivalent weight of the epoxy-containing rubber was 2,500.

Add Novolac #2000.100 to 20 parts by weight of the above rubber.
After adding parts by weight and removing distilled water from the system by vacuum drying, the mixture was melt-mixed at 180'C for 60 minutes with stirring to obtain a rubber-modified phenol resin (C).

Synthesis Example 4 Rubber-modified phenol resin CD) 25 parts by weight of the rubber-modified phenol resin (C) obtained in Synthesis Example 3 was added with a resol type phenol resin (Showa Kobunshi type, IBR).
P) 100 parts by weight were pulverized and mixed to obtain a rubber-modified phenol resin (D).

Synthesis Example 5 Rubber-modified phenolic resin (E) 20 parts by weight of carboxyl group-containing NBR and Novolank #
Add 100 parts by weight of 2000.100 parts by weight and melt-mix at 180°C for 30 minutes with stirring to obtain rubber-modified phenolic resin (E).
I got it.

Synthesis Example 6 Rubber modified phenolic resin (F) Novolac #2000 in high styrene SBR15mf part
．． 100 parts by weight was added and melt-mixed at 180°C for 30 minutes with stirring to obtain a rubber-modified phenolic resin (F).

Synthesis Example 7 Rubber-modified phenolic resin (C) 20 parts by weight of High Styrene 5BR and Novolac #2000
．． 100 parts by weight was added and melt-mixed at 180°C for 30 minutes with stirring to obtain a rubber-modified phenolic resin (G).

Examples 1-4. Comparative Examples 1 to 3 Hexamethylenetetramine and glass fiber (manufactured by Central Glass, εC3O) were added to the rubber-modified phenolic resin obtained in the synthesis example.
3-167K, cut length 3IIIl silane treated product),
The inorganic filler and other additives were mixed in the proportions shown in Table 1, and the mixture was roll-kneaded for 6 minutes at a temperature of 95 to 100 °C with the front roll and 55 to 60 °C with the rear roll, and then kneaded in a power mill ( The mixture was pulverized and sized using a 4+1-screen IJ-screen to obtain a composition.

The following extrusion molding test was conducted on the obtained composition to obtain a platen roll. The evaluation results of the obtained platen roll are shown in Table 2.

Example 5 Glass fiber (manufactured by Central Glass, EC3O3-167K, cut length 311cm, silane treated product) and other additives were added to the rubber-modified phenolic resin (D) obtained in Synthesis Example 4 as shown in Table 1. After mixing in the same proportion as in Example 1 and kneading under the same conditions as in Example 1, the mixture was pulverized and sized to obtain a composition.

The following extrusion molding test was conducted on the obtained composition to obtain a platen roll.

The evaluation results of the obtained platen roll are shown in Table 2.

Example 6 The following extrusion molding test was conducted on the granulated product of the resin composition of Example 2, and a metal shaft (diameter 24+ui, length 440 mm) was inserted into the resulting platen roll to form a platen roll with metal shaft. Obtained. Table 2 shows the evaluation results of the obtained platen roll with metal shield.

Extrusion Molding Test The following extrusion molding test was conducted on the granulated resin compositions obtained in each Example and Comparative Example.

The test results are shown in Table 2.

By using an extruder with a diameter of 30W-1L/I)-22, the diameter of the bottom of the screw is 26.The diameter of the screw bottom is 26.
mm, length 90 mm (30) Using a screw with a compression ratio of 2.0 and a smooth part, each molding material was used to make a screw with a diameter of 30 mm.
- Molding an extrusion vibrator with meat turning r ¥3sm, length 3501
The platen roll was obtained by cutting into lengths of m.

The extrusion conditions are room temperature for 2D from the bottom of the hopper, and then
lOD is 60℃, 110~140 is 80℃115D ~
Extrusion was performed at 100°C for 18D, 140°C for 190-220, and screw rotation speeds of 3sr, p, -.

Platen roll evaluation method 1, Ii sound measurement Attach the platen roll and paper to the actual printer, capture the sound generated by the print head with a microphone at a position of 1 m from the platen roll, connect it to a sound level meter, and measure the highest value. did. Note that the noise reduction effect was based on hard ebonite rubber.

2. Printing characteristics A printing test was conducted with a platen roll attached to an actual printer. The state of the outline of the printed result was judged with the naked eye.

3. Number of prints until dents occur A platen roll was attached to an actual printer, a printing test was conducted, and the number of times dents appeared on the roller surface was measured.

[Effect of the invention] The platen roll of the invention has excellent printing characteristics and durability,
It has the effect of producing low noise and continuous extrusion molded products, and can be used in a wide range of fields such as copying machine parts and printing machine parts, making a great contribution to industry.

Claims (1)

[Claims] 1. Phenolic resin, glass fiber and/or
In a platen roll formed using a composition containing a desired amount of an inorganic filler and various additives as necessary, a rubber-modified phenolic resin having an epoxy group in the molecule is added to the phenolic resin. A platen roll characterized in that it is molded from a composition formed by crosslinking the same. 2. Claim 1 covering layer of metal shaft or metal pipe
A platen roll formed from the composition described above.