JPH04357033A - Manufacture of composite vibration damping material - Google Patents

Abstract

PURPOSE:To make the variability of the characteristics of product smaller and homogenize the product by a method wherein the degree of progress of the hardening reaction of resin composition containing chief material and hardener is continuously grasped on production line so as to feed the result backward to the operating conditions such as heating temperature, heating time and the like. CONSTITUTION:The absorption spectra of radicals participating in the reaction of the chief material and/or hardener held in resin composition 16 or of radicals produced anew by hardening reaction are measured with a spectrophotometer 28 just after the application of the resin composition with a coating device 12 and with a spectrophotometer 30 just before the contact bonding of the resin composition with a contact bonding device 20. The measured results are sent to a controlling device 32 so as to calculate B/A or the ratio of the absorption spectral band intensity B just before the contact bonding to the absorption spectral band intensity A just after the application in order to feed in response to the calculated result backward, and the preparing ratio of the hardener to the chief material in the resin composition in a preparing device 10, heating temperatures at heating devices 18 and 24 and thermal contact bonding temperature, pressure and the like at the contact bonding device 20 are adjusted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing composite vibration damping materials. Specifically, the present invention relates to a method for manufacturing a composite damping material that can easily produce a composite damping material with little variation in product characteristics.

0002

BACKGROUND OF THE INVENTION Reflecting the recent social emphasis on the environment, interest in noise and vibration, which are one of the environmental problems, is increasing, and many efforts are being made to solve these problems. In particular, with regard to noise, the development of materials for noise prevention is active, as related legislation such as the Noise Control Act, which focuses on automobile noise, has been fleshed out and is being implemented.

[0003] Against this background, there has been a demand for materials that have a damping effect, and in particular, composite vibration damping materials in which an intermediate resin layer made of viscoelastic resin is interposed between two metal plates have been developed to reduce noise and vibration. It is attracting attention as a prevention material.

[0004] This composite vibration damping material has an intermediate resin layer that converts vibrations applied to a metal plate into thermal energy, and can be widely used in the automobile industry, civil engineering and construction industry, electrical industry, etc. For example, it is being used or is being considered for applications such as engine oil pans, stairs, doors, flooring materials, building materials such as roofing materials, and covers for motors and compressors.

Generally, the damping performance of such a composite vibration damping material (hereinafter referred to as "damping material") depends on the performance of the intermediate resin layer. Then, this damping performance is expressed as the loss coefficient (η)
It is known that η has a characteristic that shows a peak at a certain constant temperature, and that damping materials are most effective when used near this peak characteristic temperature.

[0006] Conventionally, as the intermediate resin layer of the damping material, polyurethane (Japanese Patent Application Laid-open No. 19277-1982), polyester (Japanese Patent Application Laid-open No. 50-143880), polyamide (Japanese Patent Application Laid-open No. 51-79146), polyisobutylene have been used. (
No. 54-43251), ethylene/α-olefin (No. 55-84655), EVA (No. 57-3)
No. 4949), crosslinked polyolefin (No. 59-15)
No. 2487), polyvinyl acetal (No. 60-8)
8149), etc., and other materials such as asphalt, synthetic rubber, acrylic adhesive, and epoxy resin are also known to have vibration damping properties. However, since such resin materials have a low cohesive force of the resin itself, their adhesive strength with metal plates is low, and it is often seen that the adhesive strength required as a structural material cannot be obtained.

Therefore, when applying these resin materials as an intermediate resin layer, a corresponding curing agent (crosslinking agent) is added to the resin material as the main component in order to improve the adhesive strength between the metal plate and the intermediate resin layer. ) is used, which is a so-called two-component curing resin material.

[0008] A vibration damping material in which such a resin material consisting of a base resin and a hardening agent is applied as an intermediate resin layer is generally prepared by dissolving a predetermined amount of the base resin and hardening agent in a solvent as necessary. This mixed composition of resin and curing agent (hereinafter referred to as resin composition) is supplied to a mixing tank etc. and mixed.
is applied to one side of the metal plate, the solvent is dried if the resin composition is a solvent type, or the resin composition is preheated if it is a solvent-free type, and then the other metal plate is coated. It is manufactured by laminating and pressing together.

[0009] In the method for producing such a damping material, in order to produce a damping material having good metal plate adhesion and good damping performance, it is necessary to It is necessary that the curing reaction of the resin composition has progressed to a certain degree when the metal plates are crimped.

0010

[Problem to be Solved by the Invention] In other words, when producing vibration damping materials by such a method, if the resin composition hardens too much, the melt viscosity of this resin becomes too high and it becomes difficult to mix with other metal plates. crimping becomes impossible. On the other hand, if the progress of curing is too small, the curing reaction will proceed even after pressure bonding, which is undesirable because the product characteristics of the manufactured vibration damping material will change over time.

Effects of the resin composition before pressure bonding The main manufacturing conditions that affect the progress of the reaction include the preparation of the main ingredient and curing agent of the resin composition, the preheating (drying) temperature of the metal plate and the resin composition, Examples include production line speed. Therefore, in a normal production line for vibration damping materials, the degree of progress of the effect reaction of the resin composition before crimping is estimated from the various conditions mentioned above, and various conditions are set so that the resin composition hardens to a predetermined state. is set.

However, in this method, if there are any changes in the operating conditions or the main ingredient or curing agent in the resin composition, the degree of curing of the resin composition before compression will change, making it difficult to maintain the desired characteristics. It is not possible to stably manufacture vibration damping materials that have the following characteristics.

An object of the present invention is to solve the problems of the prior art described above, and to accurately grasp the progress of the curing reaction of the resin composition immediately before compression on the production line, and to It is an object of the present invention to provide a method for manufacturing a composite vibration damping material that can stably manufacture a product having predetermined characteristics by adjusting various manufacturing conditions.

[0014]

[Means for Solving the Problems] When manufacturing a composite vibration damping material having an intermediate resin layer consisting of a base resin and a curing agent, in order to stably manufacture a product with predetermined characteristics, it is necessary to and a curing agent (
It is necessary to keep the progress of the curing reaction of the two-component curing resin) constant, and in order to perform stable production, it is essential to accurately and quantitatively understand the progress of this curing reaction. be.

However, in conventional manufacturing methods for composite vibration damping materials, the progress of the curing reaction cannot be ascertained except by estimating it from the manufacturing conditions or by sampling the mixed composition midway through the line and measuring the degree of progress. Therefore, it is not possible to grasp the progress of curing immediately before crimping on the production line. Therefore, as mentioned above, the degree of progress of the curing reaction varies due to changes in operating conditions, etc., making stable production impossible.

[0016] In order to solve these problems, the inventors of the present invention have made extensive studies and found that the mixed composition is mixed immediately after it is applied to the metal plates and immediately before the metal plates are laminated and pressed together. Measure the absorption spectrum of the groups involved in the curing reaction among the groups contained in the main ingredient and/or curing agent contained in the composition, and determine the progress of the curing reaction from the spectral intensity ratio after application and before lamination (pressure bonding). Find out what you can understand,
The present invention has been accomplished.

That is, in the present invention, after applying a mixed composition containing a main agent and a curing agent for forming an intermediate resin layer to the surface of a metal plate, another metal plate is coated on the surface of the metal plate in accordance with the coated surface of the mixed composition. Immediately after applying the mixed composition and immediately before the laminating and pressing, a group involved in the reaction of the main ingredient or curing agent,
Measure the absorption spectrum of at least one group newly generated by the reaction of the base agent and the curing agent, and adjust the manufacturing conditions so that the absorption spectrum intensity ratio immediately after application and immediately before lamination is within a predetermined range. Provided is a method for manufacturing a composite damping material characterized by adjustment.

Further, the manufacturing conditions to be adjusted include preparation of the mixed composition, preheating and drying of the mixed composition applied to the metal plate, preheating of other metal plates, production line speed, and the speed at which the mixed composition was applied. It is preferable that one or more of the following is used: crimping a metal plate with another metal plate.

The method for manufacturing the composite vibration damping material of the present invention will be explained in detail below.

FIG. 1 shows a conceptual diagram of a manufacturing line for a composite damping material that employs the method for manufacturing a composite damping material (hereinafter referred to as the "manufacturing method") of the present invention. The production line for the composite vibration damping material (hereinafter referred to as "damping material") shown in the figure is for producing a damping material in which an intermediate resin layer consisting of a main material and a hardening agent is sandwiched between two metal plates. It is.

[0021] The mixed composition (hereinafter referred to as resin composition 16) containing the main agent and curing agent forming the intermediate resin layer is as follows:
The mixture is blended by the blending device 10 and continuously coated by the coating device 12 onto the first metal plate 14 that is conveyed in the direction of arrow a. In addition, in the manufacturing method of the present invention, there is no particular limitation on the amount ratio of the main agent and curing agent to be applied, and it is
It may be the same as a damping material using liquid type resin. Furthermore, the coating device 12 applied to the manufacturing method of the present invention is not particularly limited, and any of various known coating devices such as a roll coater, doctor coater, slit coater, spray coater, etc. can be applied.

First metal plate 1 coated with resin composition 16
4 is then carried into a heating (drying) device 18 and preheated (if the resin composition 16 is a solvent type, drying is also performed)
and transported to the crimping device 20.

On the other hand, the second metal plate 22 to be pressure bonded to the first metal plate 14 via the intermediate resin layer (resin composition) is carried in from the left direction in the figure in the direction of arrow b, and is preheated by a heating device 24. After that, it is carried into the crimping device 20.

Both metal plates carried into the pressure bonding device 20 are laminated with the resin composition 16 interposed therebetween, heat-pressed to form a vibration damping material 26, and conveyed downward in the figure.

Here, the production line of the illustrated example adopts the manufacturing method of the present invention, and the spectrophotometer 28 performs the crimping (lamination) by the crimping device 20 immediately after the coating by the coating device 12 by the spectrophotometer 30. Immediately before, resin composition 1
A group involved in the reaction of the main agent or curing agent contained in 6,
Alternatively, the absorption spectrum of groups newly formed by the curing reaction is measured.

[0026] There is no particular limitation on the method of measuring the absorption spectrum used in the present invention, and any of various known spectroscopic techniques such as an infrared spectrophotometer, an ultraviolet spectrophotometer, a far ultraviolet spectrophotometer, etc. can be applied. However, in the measurement of ultraviolet absorption, an infrared spectrophotometer is preferably used since there is a risk of resin deterioration.

This measurement result is sent to the control device 32, and the ratio of the absorption spectrum intensity A immediately after coating and the absorption spectrum intensity B immediately before crimping, that is, B/A (A/B), is calculated. (Feedback) The blending ratio of the main ingredient and curing agent of the resin composition 16 in the blending device 10, the heating temperature in the heating devices 18 and 24, the temperature and pressure of thermocompression bonding in the compression bonding device 20, etc. are adjusted.

As is well known, the intensity of absorption spectra such as infrared absorption spectra increases in direct proportion to the amount of substances (groups possessed by) present in the system; for example, crosslinking in a resin composition If the amount of the crosslinking agent increases or decreases, the absorption spectrum intensity derived from the groups possessed by the crosslinking agent also changes accordingly.

Here, when a base resin or a curing agent has a group involved in the curing reaction, for example, when polyester is used as the base resin and an isocyanate compound is used as the hardener, the OH group of the polyester, the NCO group of the isocyanate compound, etc. , decreases as the curing reaction of the resin composition progresses (the number of groups generated by both reactions increases).

That is, immediately after applying the resin composition 16,
The intensity ratio of the absorption spectra of these groups immediately before compression, that is, B/A, decreases as the curing reaction progresses (A
/B becomes large), and the degree of progress of the curing reaction can be quantitatively determined from this absorption spectrum intensity ratio.

Therefore, an appropriate range of B/A spectral intensity ratio is determined in advance through experiments, etc., and various manufacturing conditions are adjusted so that the B/A actually measured on the manufacturing line falls within the appropriate range. By adjusting the degree of curing of the resin composition 16, the first metal 14 and the second metal plate 22 can be crimped together, and the damping material 26 having desired characteristics can be stably produced. can be manufactured.

The appropriate range of the spectral intensity ratio can be set, for example, by preparing a resin composition with a standard mixing ratio of the base resin and curing agent, applying it to a metal plate, and then preheating (drying) it at a predetermined heating temperature. After hardening, other metal plates are laminated and crimped. At this time, the relationship between the absorption spectrum intensity ratio immediately after application and immediately before pressure bonding, adhesive strength, and vibration damping performance is investigated. These experiments are conducted for various spectral intensity ratios by changing the heating temperature, time, etc., and the range of absorption spectral intensity ratio that provides good adhesive strength and vibration damping performance is determined, and this is determined as the appropriate range. Bye.

The absorption spectrum of the groups involved in the reaction of the main agent or curing agent contained in the resin composition 16 measured by the production method of the present invention, or of the groups newly formed by the curing reaction, depends on the applied resin composition. It may be set as appropriate depending on the object. Specifically, when a polyester resin is used as the main resin and an isocyanate compound is used as a curing agent, the absorption spectrum derived from -OH of the polyester resin and the absorption spectrum derived from -NCO of the isocyanate compound are exemplified. When an infrared spectrophotometer is used as the spectrophotometer 28, 30, 3,500
2300 derived from absorption near cm-1 and -NCO
Absorption near cm-1 may be applied.

The infrared absorption spectrum of the resin composition 16 coated on the metal plate 14 can be measured by a known method such as a total reflection method, a polarized reflection method, or a reflection method such as a diffuse reflection method. good.

Since the measurement conditions of the spectrophotometers 28 and 30, such as temperature, thickness of the coating film, and distance between the coating film and the spectrophotometer, are usually different, in order to more accurately determine the spectral intensity ratio, Absorption spectrum C that does not contribute to the curing reaction of both the resin and the curing agent and is derived from a group common to both.
may be applied as a standard spectrum. In this case, since the absorption spectra C immediately after application and immediately before pressure bonding are basically the same, it may be expressed as (B/C)/(A/C). An example of absorption spectrum C is 2850 cm-, which is derived from C-H bonds that are often contained in ordinary resins and curing agents.
The absorption spectrum derived from No. 1 can be mentioned.

In the manufacturing method of the present invention, the blending ratio of the main ingredient and curing agent of the resin composition 16 in the blending device 10, the heating device 18 and The spectral intensity ratio is controlled to be within an appropriate range by adjusting the heating temperature in 24, the temperature and pressure of heat-compression bonding in the crimping device 20, the manufacturing line speed, etc.

FIG. 2 conceptually shows an example of the relationship between B/A and heating time when the heating (drying) temperature is used as a parameter for the resin composition 16 consisting of a base resin and a curing agent. In the example shown in FIG. 2, the longer the heating time or the higher the heating temperature, the more the curing reaction progresses, and the smaller the B/A is.

Therefore, a graph showing the relationship between B/A and heating time with heating (drying) temperature as a parameter as shown in FIG. 2 is prepared in advance as a calibration curve, and then measured and calculated on the production line. By adjusting the heating time and heating temperature according to the B/A obtained, the B/A can be kept within the appropriate range, and if the B/A is too small (the reaction has progressed too much), drying By shortening the drying time (reducing line speed), lowering the heating temperature, etc.If B/A is too large (when the reaction progress is low), by increasing the drying time, increasing the heating temperature, etc. , B/A can be set within an appropriate range.

In the present invention, the method for adjusting the manufacturing conditions to keep B/A within the appropriate range is not limited to adjusting the heating (drying) conditions of the resin composition 16, but the method for adjusting the manufacturing conditions in the compounding device 10 Blending ratio of main agent and curing agent, heating device 2
The heating temperature and time of the second metal plate 22 according to No. 4, the heating temperature and pressure bonding force of the pressure bonding device 20, etc. may be changed.

For example, if B/A is too small, reduce the amount of curing agent added in the compounding device 10, increase the heating temperature of the second metal plate 22 by the heating device 24, extend the heating time, or heat the second metal plate 22 in the compression bonding device 20. This may be caused by an increase in temperature, a decrease in pressure bonding force, or the like. In addition, if B/A is too large,
Do the opposite.

[0041] In the present invention, adjustment of manufacturing conditions to bring B/A within an appropriate range may be carried out under a single manufacturing condition, or may be performed using various methods in combination.

According to the manufacturing method of the present invention, the resin composition can always be kept in a predetermined cured state before compression bonding, so that a vibration damping material with uniform properties without variations in damping properties, adhesiveness, etc. can be produced. can be manufactured.

The manufacturing method of the present invention includes applying a resin composition to one of the metal plates 14 and heating (drying) it as described above, and then press-bonding it with the other metal plate 22. Apply resin composition 16 to the board and heat (dry) both.
It can also be adopted as a method of laminating and crimping them together. In that case, the resin compositions coated on both metal plates may be measured using the spectrophotometer shown in FIG.

[0044] In the manufacturing method of the present invention, there is no particular limitation on the metal plate that can be applied, and cold rolled steel plates,
Surface-treated steel plates such as chromate-treated steel plates, zinc-based plated steel plates, and phosphate-treated steel plates, as well as copper plates, aluminum plates, stainless steel plates, titanium plates, and the like may be used. Further, the shape may be either a coil shape or a cut plate shape.

There is no particular limitation on the thickness of the metal plate, but a thickness of about 0.2 to 2 mm is usually suitably used.

[0046] The intermediate resin layer (resin composition) in the production method of the present invention is a two-component curing type resin consisting of a main resin and a curing agent. As the main agent that can be applied, any of the various materials that are applied to the intermediate resin layer of ordinary vibration damping materials can be used, and in particular, crosslinkable materials containing two or more crosslinkable functional groups in one molecule can be used. Examples include thermoplastic resins. here,
The crosslinkable functional group refers to a group that reacts with the curing agent (crosslinking agent) described below, and specific examples include hydroxyl group, epoxy group, amino group, carboxyl group, isocyanate group, acid anhydride group, etc. be done.

Specifically, the thermoplastic polyester resin having the hydroxyl group and carboxyl group, the epoxy modified resin having the epoxy group (glycidyl group), and the functional group-containing diene resin having a double bond in the molecule. ,
Examples include polyamide resins having the amino group, carboxyl group, and acid amide bond, and modified polyolefin resins having the acid anhydride group and carboxyl group.

[0048] The curing agent is a curing agent that reacts with the functional groups of such thermoplastic resins to form a molecular structure. Therefore, the curing agent only needs to have two or more functional groups capable of reacting with the functional groups of the thermoplastic resin, and is selected depending on the type of the thermoplastic resin.

[0049] Examples include isocyanate-based, epoxy-based, acid anhydride-based, amine-based, aziridyl-based, and oxazoline-based compounds, but when using a thermoplastic polyester resin in which the thermoplastic resin has a carboxyl group, If the isocyanate type or epoxy type uses an epoxy resin having an epoxy group, the acid anhydride type or amine type uses the isocyanate type or diene type resin having a hydroxyl group, carboxyl group, or amino group. When using a polyamide resin in which the isocyanate type, epoxy type, or acid anhydride type has an amino group, carboxyl group, or acid amide bond, the isocyanate type, epoxy type, or acid anhydride type has an acid anhydride group or carboxyl group. When using a modified polyolefin resin having a polyolefin resin, examples thereof include amine type, isocyanate type, and epoxy type.

Further, as described above, the base material (thermoplastic resin) and the curing agent are dissolved in a solvent and applied to the metal plate, if necessary. The solvent may be appropriately selected depending on the type of the main agent, and specific examples include toluene, MEK, xylene, acetone, chloroform, MIBK, and ethyl acetate.

[0051] In addition to these components, various additives may be added to the intermediate resin layer to which the manufacturing method of the present invention is applied, if necessary. Additives include tackifying resins such as polyester resins, epoxy resins, styrene resins, terpene resins, terpene phenol resins, rosin resins, hydrocarbon resins, aromatic resins, and phenolic resins, polyalkylene glycol polyester plasticizers, etc. curing agents, such as melamine resins, silane coupling agents,
Examples include metal salts and chain extenders. Inorganic fillers such as calcium carbonate, talc, and hard seal may also be added.

Furthermore, stainless steel, zinc,
By blending a conductive solid substance such as copper, tin, or nickel, conductivity can be imparted to the composite damping material to make it spot-weldable.

Although the method for manufacturing the composite vibration damping material of the present invention has been described above in detail, the present invention is not limited thereto, and various improvements and changes can be made without departing from the gist of the present invention. Of course, you can also do this.

[0054]

[Examples] Hereinafter, the present invention will be explained in more detail with reference to specific examples.

Polyester (manufactured by Toagosei Kagaku Kogyo Co., Ltd., number average molecular weight 13,500; OH number 3.7×1
0-5 mol/g) and an isocyanate compound (manufactured by Nippon Polyurethane Industries, Ltd., NCO group number 1.8) as a curing agent.
x 10-3 mol/g), cold-rolled steel plates were used as the metal plates 14 and 22, and a damping material was manufactured by the manufacturing method of the present invention on a manufacturing line to which the manufacturing method of the present invention is applied, as shown in FIG.

First, using MEK as a solvent, resin composition 16 was prepared by mixing 3 parts by weight of an isocyanate compound with 100 parts by weight of the above-mentioned polyester, and immediately after coating on a metal plate, absorption spectrum A was obtained for NCO groups. The resulting stretching vibration (near 2500 cm-1) was measured. Subsequently, this resin composition was heated to 160, 180, 200, and 220°C.
The sample was heated and dried at each temperature, and after the drying was completed, the same spectrum intensity was measured as absorption spectrum B. FIG. 3 shows the relationship between the absorption spectrum intensity ratio B/A at each heating temperature and the drying time.

Next, the metal plate coated with the resin composition thus obtained was immediately heat-pressed to another metal plate at the same temperature as the heating and drying temperature and under a surface pressure of 30 kgf/cm2. The adhesive strength was measured by T-peel strength and tensile shear strength. Based on this result, the absorption spectrum intensity ratio B/A was set in the range of 0.5 to 0.6.

Under these conditions, the production line shown in FIG.
The infrared absorption spectrum near 2300 cm −1 derived from NCO is measured, the control device 32 calculates B/A, and the heating device 18 heats (dries) the B/A so that it falls within the above setting range. When the damping material 26 was produced while controlling the temperature, it was possible to stably and continuously produce a damping material having predetermined characteristics (performance).

[0059] Also, the heating temperature 18 in the heating device 18
When the absorption spectrum intensity ratio B/A was within the set range at 0°C and heating time of 3 minutes, when the heating temperature was increased to 220°C, B/A deviated from the set range and the obtained control The material was a defective product with low adhesive strength.

From the above results, the effects of the present invention are clear.

[0061]

[Effects of the Invention] As explained in detail above, by adopting the manufacturing method of the present invention, the curing reaction of the resin composition containing the base resin and the curing agent can be progressed on the production line of composite vibration damping materials. By feeding back the results to operating conditions such as heating (drying) temperature and heating time, we can continuously produce homogeneous composite vibration damping materials with small variations in product properties. Obtainable.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of an example of a production line to which the method for producing a composite vibration damping material of the present invention is applied.

FIG. 2 is a graph conceptually showing the relationship between absorption spectrum intensity ratio and heating time using heating temperature as a parameter.

FIG. 3 is a graph showing an example of the relationship between absorption spectrum intensity ratio and heating time using heating temperature as a parameter.

[Explanation of symbols]

10　Blending device 12 Coating device 14 First metal plate 16 Resin composition 18, 24 Heating device 20 Crimping device 22 Second metal plate 26 Composite vibration damping material 28, 30 Spectrophotometer 32 Control device

Claims (2)

[Claims] 1. After applying a mixed composition containing a main agent and a curing agent for forming an intermediate resin layer to the surface of a metal plate, another metal plate is laminated and crimped to match the surface to which the mixed composition is applied. In the method for producing a composite vibration damping material, immediately after applying the mixed composition and immediately before the laminating/pressing, a group involved in the reaction of the base material or the curing agent, which is newly generated by the reaction of the base material and the curing agent. A composite damping material characterized in that the absorption spectrum of at least one of the groups is measured, and manufacturing conditions are adjusted so that the absorption spectrum intensity ratio immediately after application and immediately before lamination falls within a predetermined range. manufacturing method. 2. The adjusted manufacturing conditions include preparation of the mixed composition, preheating drying of the mixed composition applied to the metal plate,
Preheating another metal plate, manufacturing line speed, crimping the metal plate coated with the mixed composition with another metal plate, or any one of the following:
The method for manufacturing a composite vibration damping material according to claim 1, which is the above.