JPS608032B2 - thermosetting adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to adhesives, particularly adhesives from 100o to
The present invention relates to a thermosetting adhesive that can be cured in a short time in a relatively low temperature range of 150 qo and has excellent heat resistance.

Crystalline saturated polyesters are used in large quantities as fibers and films, but they are not used as adhesives.

The reason for this is that even if crystalline polyester is melted and bonded, when it is cooled, the crystals rapidly grow in random directions and turn into a white powder. However, when condensation is performed using two or more acids or polyhydric alcohols,
It is an amorphous or relatively soft polymer with low crystallinity and can be used as an adhesive. Amorphous or relatively soft polyester with low crystallinity,
In addition, it is synthesized by reacting a crystalline polyester with a dibasic acid or a polyhydric alcohol different from the alcohol or alcohol used in its synthesis. However, the biggest disadvantage of amorphous or relatively soft polyester adhesives with low crystallinity is their heat resistance and
These include lack of solvent resistance and low shear strength.
On the other hand, eboxy resin is currently widely used as an adhesive for metals, inorganic materials, and other materials, and has the advantage of high shear strength and creep strength, but it also has the advantage of high shear strength and creep strength. It has the disadvantage of extremely low strength.

For example, with ordinary epoxy resin, a shear strength of 100 kg/base can be easily obtained, but the strength of one roll is 0 to 2 k9.
'in only moderate. Practically, the latter is removed,
Strengths such as bending, slope, impact, and fatigue are important, and peel strength is a rough guide for adhesive properties.
If the peel strength is between 6 and 7 k9/in, it can be used as an adhesive for most purposes. Epoxy resins with a peeling strength of more than 10k9/n are hardly ever sold. Epoxy resin is very famous as an adhesive, and although many years have passed since its development, the reason why its usage is small today is because it has low strength against peeling, bending, shaking, impact, and fatigue. . In order to improve this drawback, a technology has been developed and sold that uses soft polymers (nylon, urethane, various rubbers, etc.) mixed with epoxy compounds. However, it is currently very expensive and is rarely used for applications other than aircraft and spacecraft. We previously discovered that a one-component heat-curing paste adhesive obtained by kneading amorphous polyester with an epoxy resin and a latent curing agent has high peel strength, and filed a patent application for this adhesive.

This paste adhesive disclosed in Tokukan Sho 51-125427 is an excellent adhesive that has high strength against peeling, bending, tearing, impact, fatigue, etc., as well as high strength against shearing and creep. The heating temperature is very high (approximately 2
00oo). Further, the form used is also limited to a paste form. Z
Accordingly, an object of the present invention is to provide an adhesive having high strength against shear, creep, peeling, bending, deformation, impact, fatigue, etc. Another object of the present invention is to add a curing agent to a mixture of a modified polyester resin and an epoxy compound and heat the mixture to 100oC.
The object of the present invention is to provide a thermosetting adhesive that can be bonded in a relatively low temperature range of 0 to 2150 oo.

As a result of various studies, the present inventors added an imidazole curing agent containing a triazine ring to a mixture of a modified polyester resin and an epoxy compound.
A thermosetting adhesive that has excellent shear strength when cured in a relatively low temperature range of 5,000 ℃, and can be used as a paste type, solution type, or adhesive thermosetting film depending on the purpose of use. I was able to obtain the drug.

The following modified polyester resins are used in the present invention.

○} Ether-type polyester obtained by treating and modifying crystalline polyester with glycols or a mixture of glycols and dibasic acid {2} Heat treating crystalline polyester with dibasic acid (including its ester) and glycols Co-condensed polyester obtained by
A polyester obtained by condensation polymerization using new raw materials of dibasic acid or its ester and glycol, which softens at room temperature (2000).

[Specifically, the elastic modulus at room temperature (20°C) is 1 pid/e/
The following are preferred. ] This is stated in [1]
' Polyester is produced by heating polyethylene terephthalate with one or more glycols other than ethylene glycol to exchange the ethylene glycol in polyethylene terephthalate with the glycols used, as detailed in Japanese Patent Publication No. 43-20313. Particularly preferred is one obtained by replacing about 30 to 100% of the ethylene glycol in polyethylene terephthalate with one or more glycols other than ethylene glycol. Such glycols include polymethylene glycols with the general formula ○(CH2)nOH (n=3 to 20) such as trimethylene glycol, tetramethylene glycol, bentamethylene glycol, hexamethylene glycol, etc., diethylene glycol, General formula KO (CH2CH2
0) n-20 days (n=2-100) polyethylene glycols, or alkylene glycols such as propylene glycol, butylene glycol, neobentyl glycol, hexylene glycol, octylene glycol, cyclohexane-1,4-dimethanol, etc. Alternatively, glycols having an aromatic group between two OHs are used.

The purpose of using polyester is to use the polyester shoulder as an effective material from the viewpoint of preventing pollution or making effective use of the plastics layer, and it is an economically preferable method.

On the other hand, examples of {3' dibasic acids or gestations thereof include terephthalic acid, isophthalic acid, p-8-oxyethoxybenzoic acid, diphenylsulfone dicarboxylic acid, diphenoxychetane dicarboxylic acid, adipic acid, sebacic acid, azelaic acid, biphenyl Carboxylic acid, naphthalene dicarboxylic acid, or its ester is used. Examples of glycols include ethylene glycol, propylene glycol, butanediol neobentyl glycol,
- Glycols such as 4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-bisoxyethoxybenzene, bisphenol A, diethylene glycol, triethylene glycol, or diols represented by the following general formula (1) are used. It will be done.

General formula (1) U・Haya・H÷OCHCH2 city "OR20÷CH2CH bad day" However, here R,, R3 is a hydrogen atom or methyl group R2 is fCH2CH2CH2)X(CH2)y, -C
Q-C(CH3)2-CH-, -CH2-C6HI.

-CH2-* -C6QC(R,,R3)C6CH2
1, 1 C6 day 41, -C, Pan 6-, 1 C6 5 OC6 day-
, one C6 ratio S02C6 day 41, one C6 day - C6 day 41,
-C ratio C6 day 4CH2-, -C illusion 4S02C6 day 4-,
Or one C6HCH! It shall represent CH1C6day41.

More specifically and and so on.

You can also choose one or more of these. It goes without saying that in synthesizing these, reaction temperatures, reaction pressures, reaction methods, polymerization catalysts, etc. conventionally known in the field of polyesters such as polyethylene terephthalate can be used.

(For example, see Murahashi et al., Synthetic Polymer V, 1971, Asakura Shoten, Chapter 4, Japanese Patent No. 550065, British Patent No. 1260943, etc.) Select one or more of the above brewing ingredients or glycol ingredients. However, combinations selected from terephthalic acid or isophthalic acid and ethylene glycol, diethylene glycol, triethylene glycol, etc. are easily available in terms of materials;
Particularly advantageous.

As the epoxy compound which is another component of the composition of the present invention, the following types are used, including those obtained by the reaction of bisphenol A and epichlorohydrin. (20:00), it is desirable to have a liquid state and a low viscosity.

1 Bisphenol A type Epikote 81 827, 82 & 832 (Shell Chemical) DER311, 312 etc. (Dow Chemical) 2
Cyclic fatty acid type Chissonox 200221 (Chisso) 3 Glycerin type Epikote 812 (Shell Chemical) 4 Dimer acid type Epjkote 871 (Shell Chemical) 5 Novolak type Epikote 152, 154 (Shell Chemical) DEN4
31, 438 (Dow Chemical) 6 Polyglycol type DER732, 736 (Dow Chemical) *7 Phthalate type Shodyne 50 & 729 (Showa Denko) 8 Oxybenzoic acid Quik 103 (Ueno Pharmaceutical) The composition of the present invention includes the above Eboxy This objective could be achieved by using as a curing agent an imidazole compound containing a triazine ring as shown in Table 1 below.

Table 1 The 4-imidazole curing agent containing a triazine ring as shown in Table 1 above requires milder curing conditions during bonding than other epoxy compound curing agents. In addition, it has excellent stability over time when left unused.

Among other epoxy compound curing agents, when using an imidazole curing agent that does not contain a triazine ring, the temperature is 70o~
It reacts at medium to low temperatures of 100 qo, but even when left at room temperature, it reacts slightly and has poor stability over time.

Furthermore, the triazine ring has a structure similar to that of dicyandiamide, which is a curing agent for epoxy compounds, and therefore has characteristics similar to dicyandiamide. Although dicyandiamide has excellent stability over time, it requires harsher curing conditions than imidazole curing agents containing triazine rings. On the other hand, the imidazole curing agent containing a triazine ring of the present invention has a high melting point and has both the advantages of the imidazole curing agent's adhesiveness at medium to low temperatures and the stability over time of dicyandiamide. The imidazole curing agents containing a triazine ring as shown in Table 1 are named "Kyuazol Kitsune Yuichi AZNE" and "Kyuazole Kitsune Yuichi AZNE" from the Shikoku Kasei Kogyo section.
It is sold under the trade names of ``Curezol 2E4MZ-AZINE'' and ``Curezol C,.Z-AZINE''.

Fillers such as those mentioned above can be used in the epoxy compound as well as the hardening agents mentioned above.

1. Calcium carbonate 2. Magnesium carbonate 3. Clays 4. Magnesium reedate 5. Talc 6. Asbestos 7. 8. Titanium oxide 10. Glass screws, 11. Glass powder 12. Various metal powders (aluminum, copper, iron, etc.) 13. Micro/ゞRune 14 The combination of the epoxy compound spread on carbon black and the curing agent has not yet been theoretically clarified.

Therefore, when determining the combination and compounding ratio of an epoxy compound and a hardening agent, there is no other way than to do trial-and-error testing. Excellent effects can only be obtained when a specific epoxy compound and a specific hardening agent are combined with paper. It will be done. Furthermore, the degree of effectiveness of the effective combination of epoxy compound and curing agent varies depending on the blending ratio, and the above-mentioned shear/creep strength, peeling, bending, deformation, impact, fatigue, and other strengths also vary. If there is too much or too little curing agent, the adhesive strength will decrease. Further, this appropriate amount differs depending on shear strength and peel strength, and generally the appropriate amount is smaller for peel strength.
It also varies depending on the temperature and time during bonding. The most effective composition ratio of the modified polyester resin, epoxy compound, and curing agent varies depending on the type of resin and cannot be uniformly defined.

However, as the ratio of the modified polyester resin and the epoxy compound increases, the peel strength increases, but the shear strength decreases. Conversely, when the amount of modified polyester resin decreases, the peel strength decreases and the shear strength increases. When placing emphasis on peel strength in a paste adhesive, which is one type of adhesive in the present invention, the mixing ratio of modified polyester resin and epoxy compound is preferably about 10 to 50/100. Needless to say, the influence of the filler is also taken into account. The mixing ratio of the filler to the epoxy compound is preferably from 0 to 100, preferably from 10 to 60/10. Next, for a solution-type adhesive, the mixing ratio of the modified polyester resin and the epoxy compound is preferably 10 to 250/100, and preferably 40 to 150/10q.

The mixing ratio of the filler to the epoxy compound is 0 to 200.
/100, preferably 50 to 100/10. Diluent solvents for this type include methylene chloride, ethylene chloride, cyclohexanone, and tetrac.
It is desirable to use a single solvent such as loethane or trichlene or a mixed solvent such as methyl ethyl ketone/toluene, methyl ethyl ketone xylene, toluene/cyclohexanone, etc. For adhesive film adhesives, the mixing ratio of modified polyester resin and epoxy compound and the mixing ratio of filler to epoxy compound are almost the same as those for solution-based adhesives, but the one with a slightly lower content of modified polyester resin The one is preferable. Until now, many adhesive films have been commercially available, but there is no one on the market that exhibits a strong adhesive force by curing after temporary fixation using adhesive force as in the present invention, and there is no film on the market that exhibits strong adhesive force as described in the past literature. I can't do it. Until now, substances and various polymers (including those containing curing agents and the like) that are adhesive, can be heat-cured, and have a certain degree of film properties have not been seen. There is no single product that has all three of the above properties, and in the case of compounding, it depends on the compatibility and solubility of each substance (when producing it as a film, it is a thermosetting type, so it cannot be melt extruded). However, a good method has not yet been discovered. On the other hand, in the adhesive of the present invention, the modified polyester resin has good compatibility with epoxy compounds commonly used as curable resins, and also has excellent solvent properties.

That is, in the present invention, by adding a specific curing agent to a composition consisting of a modified polyester resin and an epoxy compound, it was possible to obtain an adhesive that exhibits strong bush Z adhesion for three types of applications. Next, as a method for producing the adhesive according to the method of the present invention, any method may be used as long as a modified polyester resin, an epoxy compound, a curing agent, and, if necessary, a filler can be uniformly mixed in Z for the paste adhesive. For example, any one of a kneader, a ball mill, a takazuka kettle, etc. can be used.

The solution type is also similar and only contains a diluting solvent. For adhesive-curing films, a solution-type film is impregnated or applied to a base material such as non-woven fabric, Japanese paper, cheesecloth, gauze, glass fiber cloth, dry cloth, other cloth, or wire mesh, and the solvent is evaporated. remain. The adhesive obtained according to the present invention has the following advantages depending on its use. 21 Paste-like adhesive [1] Since it is a paste-like adhesive, it can be applied to any shape of adherend.

■ Since it does not use organic solvents, there is no pollution caused by solvents and it is safe from an occupational health standpoint. 8 3 Legs Since it is a one-component type, there is no need for kneading.

[4- Curing temperature is relatively low (about 100~150oo
) Also, it cures in a short time (about 1 minute), making it easy to use and shortening the time it takes to reach the required strength.

3. When bonding using the adhesive obtained by this method, the shear strength is approximately the same as when using epoxy resin, but the peel strength is lower than when using epoxy resin. Since it is about several times to 10 times, vibration,
It is particularly suitable for use in locations subject to fatigue, shock, etc.

2 Solution type adhesive m Can be applied to any shape.

For example, it is suitable for can manufacturing.

{2) Easy to handle due to low viscosity.

'31 Since it can be coated thinly, it can also be used as a paint film. 3 Adhesive Curable Film '11 Since it is in the form of a film, it is easy to handle.

'21 Since it has adhesive properties, it has initial adhesive strength until the adhesive hardens, making it easy to handle.

'3} Since the curing time is relatively short and it can be cured at a temperature of about 13,000 ℃, it is easy to develop adhesive strength.

The three types of adhesives obtained according to the invention have in common that they are generally not sensitive to temperature during bonding.

They have almost the same adhesive strength between 00 and 100 qo.

Effective adherends include various metals such as aluminum, steel, lead, brass, tinplate, and galvanized iron, glass, ceramics, slate concrete, inorganic materials such as various inorganic boards, polyethylene terephthalate, polyvinyl chloride, rubber, and thermosetting. Materials include polymer compounds such as synthetic resins, wood, textiles, leather, etc., but are not particularly limited.

The method of the present invention will be described in detail below with reference to Examples.

In the examples, all "parts" indicate "parts by weight." Example 1 [11 Synthesis of polyester Polyethylene terephthalate beret [intrinsic viscosity 0.6]
1 (Measured at 30 qo in a 6:4 mixture of phenol and tetrachloroethane)] 10 base parts: 100 parts of triethylene glycol, 0.05 antimony oxide as a catalyst
About 2 parts were added to the reactor, and about 2 parts
The reactor was heated at 6,000 °C to carry out a transesterification reaction, and then the pressure in the reactor was gradually reduced to less than 1% Hg at about 270 °C for about 3 hours. Due to the condensation reaction, an almost amorphous soft polyester ( A) was obtained.

This polyester (A) has an elastic modulus of 23001 = 8x1 = d skin e/, and is a soft resinous material. '2} Preparation of adhesive Next, polyester (A), liquid eboxy compound Epiclone 830 (Pisphenol F type epoxy compound manufactured by Dainippon Ink, epoxy equivalent: about 18, powder weight: about 360), talc powder, and Curesol as a hardening agent. 2MZ-AZI
Four types of NE (imidazole curing agent manufactured by Shikoku Kaseiran Co., Ltd.) were mixed in the proportions shown below to prepare paste-type, solution-type, and adhesive-curing film adhesives.

Each type was glued with 13000, 1 powder. [
1} Paste 100 50 The above formulation was kneaded in a kneader to form a paste, which was used as it was.

t2) Solution type 100 The above formulation was mixed with methyl ethyl ketone/toluene (1/
A 50% solution of 1) was prepared, applied to an adherend, dried, and thermally bonded.

'31 Adhesive curable film polyester (A) 7$ parts Epicron 830 100 Talc powder
100 Kyuazor 2M Low A
ZNE 5'' The above formulation is made into a 70% solution of methyl ethyl ketone notolene (1/1), and approximately 80%
Approximately 250
It was made into a thick film.

[3- Adhesive strength test] The shear strength and peel strength of the paste-type, solution-type, and adhesive-curable films bonded together were measured by the methods shown below, and the results are shown in Table 2.

{a) Shear strength o Adherent: Bright steel plate (JISG-3141) Thickness 3
It was used after washing the skin with Triclean steam and drying it.

o Adhesion conditions: A paste adhesive was sandwiched between steel plates, and the adhesive layer was adjusted using a 300-piece baser.

The wrap length is 0.5 inch. It was placed in a 130 qo heat press for hardening.

o Measurement method: Based on ASTM D-1002-64, (
Crosshead speed 0.2 sails per minute) {b} Peeling strength o Adherent: Aluminum plate (manufactured by Nikkei Rolling Co., Ltd. Purity 9
9.5% hardness 1/thickness 250 France) o Adhesion conditions: Paste adhesive is sandwiched between aluminum plates and the adhesive layer is
It was adjusted using a 300-meter smoother.

It was cured by placing it in a 13,000° heat press for 10 minutes.

oMeasurement method: Based on ASTM D-1876-69 (crosshead speed 3 m/min) As shown in the upper table of Table 2, polyester (A), Epicron 8
Three types of adhesives were able to be prepared using 30, talc powder, and Curesol 2MZ-AZINE as raw materials.

All of these have excellent adhesive strength. Example 2 [1] Synthesis of polyester Polyester (B) [modulus of elasticity (23q○) 5×1 and dyne/] was carried out in the same manner as in Example 1 using the following composition.
was synthesized.

100 parts 6 Akebono K T Harutoku Roken Zhuo Sansan Xiao Shufan 45 parts Adduct of Ru 17 parts Antimony oxide 0.1 part (2') Preparation of adhesion agent Next, polyester (B) and liquid epoxy compound Epiclone 830 (Bisphenol Zhl F type epoxy compound manufactured by Dainippon Ink, epoxy equivalent: about 180, molecular weight: about 360
) Curesol 2MZ- as talc powder and curing agent
Four types of AZNE (imidazole curing agent manufactured by Shikoku Kasei Corporation) were mixed in the proportions shown below to prepare adhesives of paste solution type and adhesive curing type Z film.

Each type was bonded at 13,000 yen in 10 minutes. '1
'Paste-like polyester (B) 15 parts
0〃Kyuazor Kasa-AZ
NE 5〃Tough Adhesive Curing Film Polyester (B) 5 Anchor Epicron 830
100 Talc powder
100 Kyuazorkasa-AaNE
5. The preparation method for each type of pasty solution-type adhesive curable film is the same as in Example 1.

t3' Using the same measuring method as in Example 1, the shear strength and peel strength were measured and the results are shown in Table 3.

As shown in Table 3 above, polyester (B), Epiclone 8
30. Three types of adhesives can be made using Kyuazol AZINE and talc powder as raw materials.

The formulation of this example had particularly excellent shear strength in the paste form, and particularly excellent peel strength in the solution form. Further, the adhesion in this example showed good adhesion at any measurement temperature from oo to 80.

Example 3 '1} Synthesis of polyester 10 parts of polyethylene terephthalate were used as a catalyst with 4 parts of triethylene glycol and 2 moles of ethylene oxide adduct of bisphenol A, and 0 parts of antimony oxide.
．． Synthesis was carried out in the same manner as in Example 1 using 05 parts.

This polyester (C) has an elastic modulus of 9×10 7 d/base at 23 oo. {2} Preparation of adhesive
Next, polyester (C) and liquid epoxy compound Epiclone 830 (Bisphenol F type epoxy compound manufactured by Dainippon Ink, epoxy equivalent of about 18
0 molecular weight (approx. 360) and curing agents such as Curesol, Shuichi AZINE, 2E Kosaichi AZNE, C, . Z-ZO
Using three types of INE (imidazole curing agent manufactured by Shikoku Kaseiran), adhesive curable films having the following formulations were prepared.

All formulations were bonded at 130°C for 1 minute. m {Keizo delusion rate ko ÷ skin NE; sardine ■ {Wang Zhuoki words and phrases ＾ Hada Misaki; Teigiri '3} also table-rolled Keizo 2 legs NE handsha fog [31 Measurement method similar to adhesive strength test example 1 The shear strength and peel strength of the adhesive curable film were measured using the following method, and the results are shown in Table 4.

As is clear from the table above in Table 4, “Curesol 2MZ-AZI
NE'' as a hardening agent showed good results in both shear strength and peel strength.

Other ``Cyuazor 4MZ-Gender INE'' and ``Cyuazor C, Z-Rudder INE'' also showed approximately the same excellent effect.

Claims (1)

[Claims] 1. A thermosetting adhesive characterized by adding an imidazole curing agent containing a triazine ring to a composition consisting of a modified polyester resin and an epoxy compound.