JPH07137265A - Method for connecting ink jet printer recording head - Google Patents

Abstract

PURPOSE:To sufficiently endure against an environmental change, a left to stand for a long period by enhancing a connecting strength of a component of a print head for an ink jet printer. CONSTITUTION:A nozzle film 4 is formed of a PES(polyether sulfone) film or a PEN(polyethylene naphthalate) film, an ink channel plate l is formed of a PPS(polyphenylene sulfide) resin, and a partition wall film 3 of a piezoelectric element(PZT) 2 is formed of an aramid (aromatic polyamide) film. These members are adhered by curing with two-liquid epoxy adhesive having epoxy resin, alicyclic amine or aromatic amine curing agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of joining print head components in an ink jet printer.

[0002]

2. Description of the Related Art Conventionally, when various device parts are joined or parts of various devices are joined, the surface of the parts is often left as it is, that is, the joining is performed untreated, and the adhesive force is too strong. did not become. Factors that influence the joining of components include the material of the component, the roughness and cleanliness of the component surface, the type of adhesive, the material of the component and the surface condition of the adhesive. Optimum values of these factors are selected for joining, but sufficient adhesive strength was not obtained in the case of materials that are difficult to join, such as PPS (polyphenylene sulfide) and aramid. Particularly in an ink jet printer, joining of parts of a print head requires considerably higher joining strength than joining of parts of other devices.

[0003]

The ink jet ink contains a strong organic solvent for dissolving the dye which is a coloring agent in order to improve the reliability of ink jet. The organic solvent in the ink easily dissolves the adhesive at the joint portion of the head unit, but slight peeling at the joint portion of the head is not allowed.

When the temperature rises and the temperature of the ink inside the head rises, the ability of the organic solvent to dissolve the adhesive increases. The joint strength of the joint must be sufficient to withstand such a case. In addition, when left for a long period of time, peeling of the joint may gradually progress,
It must also have long-term durability. Furthermore, since the width of the joint portion of the ink flow path plate is extremely narrow, such as several tens of μm to several hundreds of μm, the bonding strength of the adhesive must be strong. Therefore, various methods for increasing the bonding strength of the head component have been tried, but none of them has achieved sufficient bonding strength.

The present invention is intended to solve the above-mentioned problems, and an object thereof is to enhance the bonding strength of components of a print head in an ink jet printer so that it can withstand environmental changes and long-term storage. It is to provide a joining method.

[0006]

According to a first aspect of the present invention, there is provided a method for joining a recording head for an ink jet printer, comprising:
A PES (polyether sulfone) film or a PEN (polyethylene naphthalate) film is used as a nozzle film as a material for a head part of an inkjet printer, and an ink flow path plate is a partition film with a PPS (polyphenylene sulfide) resin and a piezoelectric element PZT. When using an aramid (aromatic polyamide) film,
It is characterized in that these members are cured and bonded with a two-component epoxy adhesive consisting of an epoxy resin and an alicyclic amine-based or aromatic amine-based curing agent.

In the joining method according to claim 2, the main component of the two-component epoxy adhesive is bisphenol A epoxy resin, bisphenol F resin, or bisphenol Z.
It is characterized in that it is one of the resins.

In the joining method according to claim 3, the curing agent for the two-component epoxy adhesive is alicyclic amine and salicylic acid.
Alicyclic amine and p-toluenesulfonic acid, alicyclic amine and 2-ethylhexanoic acid, alicyclic amine and cresol, alicyclic amine and carboxylic acid, alicyclic amine and isopropylphenol It is characterized by

In the bonding method according to claim 4, the curing agent for the two-component epoxy adhesive is an aromatic amine and salicylic acid.
It is characterized by comprising one of an aromatic amine and p-toluenesulfonic acid, and an aromatic amine and 2-ethylhexanoic acid.

In the joining method according to the fifth aspect of the present invention, the amount of salicylic acid, p-toluenesulfonic acid, 2-ethylhexanoic acid, cresol, carboxylic acid, or isopropylphenol added to the alicyclic amine or aromatic amine is 0. 5
It is characterized by being 10 wt%.

When joining parts of an ink jet printer recording head, the material and shape of the parts, surface condition and roughness, cleanliness, kind of adhesive, etc., which are factors affecting the joining, are optimized. There is a need to.

FIG. 1 is a perspective view showing the structure of a piezo type print head in an ink jet printer to which the present invention is applied, and FIG. 2 is an enlarged cross section of its joint.
On the ink flow path plate 1 having a flow path through which the ink passes and the PZT of the piezoelectric material 2, the partition film 3 made of a material which is insoluble in the ink and is insoluble in the ink is further laminated by bonding.
Next, the ink flow path plate 1 is bonded onto the partition film 3, and the nozzle film 4 is bonded further. The ink comes into contact with only the joint portion of the nozzle film 4, the ink flow path plate 1 and the partition film 3. In FIG. 1, 5 is a glass plate, 6 is a protective plate, 7 is a substrate, and in FIG.
8 is an adhesive.

Further, during printing, a pulsed pressure is constantly applied from the piezoelectric material 2 through the partition film 3. After joining, it is necessary to join the ink flow path plate 1 and the partition film 3 so that the joining stress at the joining portion is not applied as much as possible. When the bonding stress is applied, the force exerted on the peeling is applied accordingly. Therefore, as described above, the peeling force is exerted by the external influence such as the liquid contact with the ink and the deformation of the member as described above. Therefore, the joining force must be larger than this peeling force.

The ink flow path plate 1 and the partition film 3 are laminated by bonding an adhesive 8. Since the ink comes into contact with this portion and is subjected to stress as described above, a tough material is used. A material that satisfies the function of a piezo type print head and has high mechanical strength is selected.
The materials for the nozzle film, the flow path plate and the partition film must be those that do not dissolve in the solvent that dissolves the dye in the ink, but that firmly adhere to the adhesive. However, most of the members that are difficult to dissolve in these solvents are difficult to bond with an adhesive.

Usually, in order to firmly bond members with an adhesive without melting the members to be bonded, it is necessary to control factors that affect the joining of parts, such as the material of the adhesive and the member and the surface condition of the member. Optimum adhesion conditions can be obtained by. However, when manufacturing a print head for an inkjet printer, the joint strength is still insufficient,
It is difficult to guarantee durability. Therefore, the above problem is solved by joining the PES (polyether sulfone) film, which is the nozzle film, the PPS (polyphenylene sulfide) resin, which is the material of the ink flow path plate, and the aramid film, which is the partition film, with the following adhesive. Can be achieved. The nozzle film is PEN
A (polyethylene naphthalate) film may be used.

The chemical structure of the material of the head part of the ink jet printer is shown in [Table 1].

[0017]

[Table 1]

As an adhesive for adhering the nozzle film, the ink flow path plate, and the partition film of the three components to which the ink comes in contact, an epoxy adhesive is selected from various adhesives because of its adhesive strength, heat resistance and water resistance. Are suitable. Further, as the adhesive for the print head constituent member, a two-component epoxy adhesive, which can select a relatively low bonding temperature, is more suitable than a one-component epoxy adhesive having a high bonding temperature. However, depending on the combination of the epoxy resin of the epoxy adhesive and the curing agent, the bonding strength may be extremely reduced when brought into contact with the inkjet ink.

In the present invention, a combination of an epoxy resin of a two-component epoxy adhesive and an alicyclic amine-based or aromatic amine-based curing agent is used as the adhesive for adhering the components of the print head of the ink jet printer as described above. When used, the adhesive does not become brittle when it comes into contact with the ink.

Ink jet inks usually contain dyes, wetting agents, stabilizers, preservatives, water, etc. Among them, the adhesive absorbs water, and the temperature and time Water absorption proceeds accordingly. The temperature of the adhesive rises,
If the contact time with the ink becomes long, water is absorbed and the glass transition point is lowered, resulting in brittleness. By using an epoxy resin and an alicyclic amine-based or aromatic amine-based curing agent as the adhesive, the glass transition point becomes high and the adhesive does not become brittle even at a temperature of 40 ° C. or higher.

As the alicyclic amine-based curing agent, compound Nos. In the following [Table 2] and [Table 3] are used. Meta-phenylenediamine as indicated in 1, 2, 3, etc. (MPD), diaminodiphenylmethane (DDM), R (CH ₃ a material obtained by opening the benzene ring of the diaminodiphenylsulfone (DADPS) as a basic skeleton - or C ₂ The one to which H ₅ −) or Cl is added cross-links with the epoxy resin and cures to greatly improve the water resistance.

[0022]

[Table 2]

[0023]

[Table 3]

The alicyclic amine-based curing agent is a medium-temperature curing agent and usually cures at 90 to 100 ° C. When the adhesive is hardened at a high temperature, the constituent members of the print head have a stress due to thermal expansion and become a peeling force. Therefore, as in claim 5, a curing accelerator such as salicylic acid, p-toluenesulfonic acid, 2-ethylhexanoic acid, cresol, carboxylic acid, or isopropylphenol is added to the alicyclic amine or aromatic amine in an amount of 0.5 to 10 wt. %, It is possible to set the curing temperature to 60 to 70 ° C. like an aliphatic amine curing agent, and it will be considerably cured even at room temperature over time. When cured at room temperature, stress due to thermal expansion of the members to be joined can be relaxed. However, since the glass transition point is low as it is, the stress can be relaxed and the glass transition point can be increased by further increasing the temperature of the post-treatment.

As the aromatic amine type curing agent, the compound No. in the following [Table 4] and [Table 5] is used. As shown in 13, 14, 15 and the like, R (CH _{3 is used} as a basic skeleton of metaphenylenediamine (MPD), diaminodiphenylmethane (DDM) and diaminodiphenylsulfone (DADPS).
- or C ₂ H ₅ -) and those obtained by adding Cl is crosslinked with epoxy resins, greatly improves the water resistance and curing.

[0026]

[Table 4]

[0027]

[Table 5]

The aromatic amine type curing agent is a high temperature curing agent and usually cures with an epoxy resin at 100 to 150 ° C. When the adhesive is hardened at a high temperature, the constituent members of the print head have a stress due to thermal expansion and become a peeling force. Therefore, as in claim 4, a curing accelerator such as salicylic acid, p-toluenesulfonic acid, or 2-ethylhexanoic acid is used in an amount of 0.5 to 10 wt% with respect to the alicyclic amine or aromatic amine.
By adding it, it is possible to set the curing temperature to 60 to 70 ° C. like an aliphatic amine curing agent, and it will be considerably cured even at room temperature over time. When cured at room temperature, stress due to thermal expansion of the members to be joined can be relaxed. However, since the glass transition point is low as it is, the stress can be relaxed and the glass transition point can be increased by further increasing the temperature of the post-treatment.

Due to the chemical structure of the aromatic amine, it is difficult to absorb the water of the solvent of the ink, but the water absorption gradually progresses when it comes into contact with the ink for a long time. However, when the cured adhesive is contacted with the ink at 70 ° C. for a little less than 100 hours and at room temperature for about 1000 hours, the water absorption amount becomes saturated. At this time, the glass transition point of the adhesive must be higher than the ambient temperature, and the combination of the bisphenol epoxy resin and the aromatic amine curing agent satisfies this condition. No other adhesive combination meets these conditions.

By changing the addition amount of the curing accelerator, the curing temperature and the curing time can be controlled and the glass transition point of the adhesive after curing can be changed. Even if the mixing ratio of the epoxy resin and the curing agent is changed, the glass transition point can be changed, but either one becomes excessive, and the bonding strength may decrease. In order to change the curing temperature, the curing time and the glass transition point without changing the bonding strength, the addition amount of the curing accelerator may be changed. What can be done like this is peculiar to the medium temperature curing agent or the high temperature curing agent.

[0031]

EXAMPLES Next, the present invention will be described in more detail with reference to examples. Example 1 A piezo type print head in the inkjet printer shown in FIG. 1 was assembled as follows. PPS
Ink flow path plate 1 made of (polyphenylene sulfide) resin
And a aramid film having a thickness of 10 μm is used as the partition film 3 and a thickness of 100 is used as the nozzle film 4.
A μm PES (polyether sulfone) film was used. Further, the following materials were mixed and used as an adhesive for joining the respective members of the print head. Bisphenol A epoxy resin 66.0 parts by weight Compound No. Compound of 2 33.7 parts by weight p-toluenesulfonic acid 0.3 parts by weight The curing temperature was 60 to 70 ° C. The obtained print head maintained good print quality without peeling of the joint even after printing for 2000 hours.

Example 2 A print head was assembled in the same manner as in Example 1 except that the following materials were mixed and used as an adhesive. Bisphenol A epoxy resin 68.0 parts by weight Compound No. Compound of 14 31.7 parts by weight p-toluenesulfonic acid 0.3 part by weight The curing temperature was 60 to 70 ° C. The obtained print head maintained good print quality without peeling of the joint even after printing for 2000 hours.

[0033]

As is clear from the above description, according to the joining method for the ink jet printer recording head of claims 1 and 2, an epoxy resin and an alicyclic ring are used as an adhesive for the head member of the ink jet printer. Water resistance and heat resistance are enhanced by using a two-part epoxy adhesive consisting of a group amine-based curing agent or an aromatic amine-based curing agent, and even if the adhesive comes into contact with ink after joining the parts, it peels off. The long-term durability is greatly extended. Further, according to the joining method of claims 3, 4, and 5, in addition to the above effects, since room temperature curing is possible, stress during curing is relaxed, and long-term durability is further extended, The load bearing capacity is increased, and the reliability is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic structure of an inkjet printer recording head to which the present invention is applied.

FIG. 2 is an enlarged cross-sectional view of a joint portion of the recording head of FIG.

[Explanation of symbols]

 1 Ink flow channel plate 2 Piezoelectric element 3 Partition film 4 Nozzle film 5 Glass plate 6 Protective plate 7 Substrate

Claims (5)

[Claims] 1. A PES (polyether sulfone) film or a PEN (polyethylene naphthalate) film is used for a nozzle film as a material of a head part of an ink jet printer, and an ink flow path plate is a PPS (polyphenylene sulfide) resin and a piezoelectric element PZT. When an aramid (aromatic polyamide) film is used as the partition wall film with the above, these members are bonded by curing with a two-component epoxy adhesive consisting of an epoxy resin and an alicyclic amine-based or aromatic amine-based curing agent. A joining method characterized by the above. 2. The joining according to claim 1, wherein the main component of the two-component epoxy adhesive is any one of bisphenol A epoxy resin, bisphenol F resin, and bisphenol Z resin. Method. 3. The curing agent for the two-part epoxy adhesive is alicyclic amine and salicylic acid, alicyclic amine and p-toluenesulfonic acid, alicyclic amine and 2-ethylhexanoic acid,
The joining method according to claim 1, wherein the joining method comprises one of an alicyclic amine and cresol, an alicyclic amine and carboxylic acid, and an alicyclic amine and isopropylphenol. 4. The curing agent for the two-component epoxy adhesive comprises any one of an aromatic amine and salicylic acid, an aromatic amine and p-toluenesulfonic acid, and an aromatic amine and 2-ethylhexanoic acid. The joining method according to claim 1, which is characterized in that. 5. The amount of salicylic acid, p-toluenesulfonic acid, 2-ethylhexanoic acid, cresol, carboxylic acid, or isopropylphenol added is 0.5 to 10 wt% with respect to the alicyclic amine or aromatic amine. The joining method according to claim 3 or 4, which is characterized in that.