JP6508442B1 - Vulcanizing adhesive composition - Google Patents

Abstract

Add 1 to 5 parts by weight of silane coupling agent and 15 to 30 parts by weight of uncured NBR per 100 parts by weight of high ortho type novolac phenol resin having an ortho type content of 65% or more calculated from the measurement results by IR Vulcanized adhesive composition prepared as a solvent solution. This vulcanized adhesive composition is a vulcanized adhesive composition used for vulcanized adhesion of metal and NBR, and not only can prevent the contamination of the mold and the adhesive but also exhibits stable adhesion. It is effectively used as an adhesive for automobile parts such as oil seal and hub seal.

Description

  The present invention relates to a vulcanized adhesive composition. More particularly, the present invention relates to a vulcanized adhesive composition that is effectively used for the vulcanization adhesion of metal and NBR.

  Although various vulcanized adhesive compositions for NBR exist in the past, among these, those composed of a phenol resin and hexamethylenetetramine are widely used for a long time since they are easy to prepare and inexpensive. It has However, this vulcanized adhesive composition generates a gas of hexamethylenetetramine at the time of heat drying, and has the disadvantage of contaminating the inside of the drying furnace and the periphery thereof. Here, when a metal fitting coated with another adhesive is dried in the same drying oven, hexamethylenetetramine remaining in the oven may adhere to cause adhesion failure.

  The present applicant uses a novolak-type phenol resin obtained from m-cresol-p-cresol mixture as an adhesive component, to which an unmodified resol-type phenol resin is added as a curing agent, and hexamethylenetetramine is a curing agent. Patent Document 1 proposes a vulcanized adhesive of a metal and an acrylic rubber, which is not used as a binder and has a baking temperature range of about 100 to 200 ° C. to metal. There are cases where this vulcanized adhesive is likely to cause adhesion failure due to insufficient curing.

Patent No. 3594105 gazette Unexamined-Japanese-Patent No. 6-345837

  An object of the present invention is a vulcanized adhesive composition mainly composed of a phenolic resin and used for vulcanized adhesion of metal and NBR, which can not only prevent contamination of a mold or an adhesive, but is also stable It is to provide what shows adhesiveness.

  The object of the present invention is a vulcanized adhesive composition prepared as an organic solvent solution by adding 1 to 5 parts by weight of a silane coupling agent and 15 to 30 parts by weight of uncured NBR per 100 parts by weight of a high ortho type novolac phenol resin. Achieved by

  The vulcanized adhesive according to the present invention is used for vulcanizing and bonding various metals such as stainless steel plate, mild steel plate, galvanized steel plate, SPCC steel plate, copper plate, copper plate, magnesium plate, aluminum plate, aluminum die-cast plate and NBR. When used, the adhesive coating film becomes tack free and reduces the incidence without causing problems such as the occurrence of micro blisters that cause mold contamination and product contamination during rubber vulcanization molding, and the 90 ° peel test It is possible to obtain a good vulcanized adhesion state of the percentage area of remaining rubber.

  In the vulcanized adhesive of the present invention, since no hexamethylenetetramine curing accelerator is blended as a curing agent for a phenol resin, no contamination is observed in the baking furnace or the periphery thereof. This is due to the use of the highly reactive high ortho type novolac phenol resin.

  In addition, in the conventional vulcanized adhesive, it is necessary to blend NBR at a high blending ratio in order to obtain good adhesion to the NBR kneaded product, and contamination of molds and products due to this is also seen (see later). Comparative Example 5) The compounding ratio of NBR can be reduced by using a highly ortho type novolac phenol resin having high reactivity.

  In the present invention, as the high ortho type novolak phenol resin, the ortho type content calculated from the area of the ortho type absorption peak and the para type absorption peak by IR (infrared absorption spectrum) is 65% or more, preferably 70% or more More preferably, 70 to 80% of novolac phenol resin is used.

  Normal novolak phenol resin is referred to as random novolak phenol resin relative to high ortho type novolac phenol resin, but random novolac phenol resin is inferior in curability compared to high ortho type novolac phenol resin and is high in processing It often takes temperature or a long time. On the other hand, the high ortho type novolak phenol resin has high reactivity and can be suitably used as a main component of the vulcanized adhesive of the present invention.

  The high ortho type novolak phenol resin is one or more of m-cresol, p-cresol, 3,5-xylenol and 2,3,5-trimethylphenol, such as m-cresol, p-cresol and 3,5- It is obtained by reacting three of xylenol or three of m-cresol, p-cresol and 2,3,5-trimethylphenol with aldehydes.

  As the aldehyde, for example, formaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, benzaldehyde, salicylaldehyde and the like are used, and preferably, formaldehyde, acetaldehyde, salicylaldehyde is used. As formaldehyde, any of formaldehyde generating materials such as formalin aqueous solution, paraformaldehyde, hemiformal with alcohols, trioxane and the like can be used.

  The reaction of the phenols with the aldehydes is carried out with an acid catalyst at a reaction temperature of about 110-220 ° C, preferably about 120-150 ° C. By causing the reaction at such a high reaction temperature, the reaction in the vicinity of the phenolic hydroxyl group occurs preferentially, and the degree of ortho-conversion increases. As an acid catalyst, generally, weak acids such as oxalic acid and acetic acid are used, but divalent metal salts, oxides or hydroxides of divalent metals are also used, and these divalent metal compounds are acidic compounds such as the above-mentioned weak acids. It can also be used in combination with Specifically, for example, zinc acetate, zinc hydroxide or the like is used. In addition, a reaction using a trifunctional phenolic monomer without using a catalyst under a high pressure condition has also been proposed (Patent Document 2).

  As such a high ortho type novolak phenol resin, a commercially available product, for example, Shonor BRM-7174H manufactured by Showa Denko K. K. is used as it is. In addition to the high ortho type novolac phenol resin, random novolac phenol resin or resol type phenol resin can be used in combination as long as it is up to about 25 parts by weight per 100 parts by weight of the high ortho type novolac phenol resin.

  As the silane coupling agent, those containing (meth) acryloxy group, mercapto group, vinyl group, epoxy group, amino group, chloropropyl group etc. may be mentioned, preferably methacryloxypropylmethyldimethoxysilane, methacryloxypropyltritriol. Methacryloxysilanes such as methoxysilane, methacryloxypropylmethyldiethoxy group-containing silane and methacryloxypropyltriethoxysilane, mercapto group-containing silanes such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane are used.

  These silane coupling agents are used in a proportion of about 0.5 to 5 parts by weight, preferably about 1 to 3 parts by weight, per 100 parts by weight of the high ortho type novolak phenolic resin. If the usage rate is less than this, the occurrence of micro blisters can not be suppressed, while if it is used at a rate higher than this, the water-resistant adhesion becomes worse.

  As the uncured NBR, one having an acrylonitrile (AN) content of about 20 to 40% by weight, preferably about 25 to 35% by weight is used. In general, those having an AN content equal to or higher than that of the NBR to be bonded are used. The unvulcanized NBR does not contain a vulcanizing component such as a vulcanizing agent.

  Uncured NBR is used in a proportion of about 15 to 30 parts by weight, preferably about 20 to 28 parts by weight, per 100 parts by weight of the high ortho type novolak phenolic resin. If the use ratio is less than this range, the initial adhesion decreases, and adhesion becomes difficult for the NBR kneaded product having low reactivity, while if it is used in a ratio greater than this, as shown in the result of Comparative Example 5 below. Although the result of the peeling test is satisfied, the mold and the molding are contaminated, and the intended purpose of the present invention can not be achieved.

  The vulcanized adhesive of the present invention containing each of the above components as an essential component is prepared as an organic solvent solution. As the organic solvent, ketones such as acetone, methyl ethyl ketone (2-butanone) and methyl isobutyl ketone, and aromatic hydrocarbons such as toluene and xylene are used alone or in combination. When ketones and aromatic hydrocarbons are used as a mixture, it is preferable that aromatic hydrocarbons be used in a ratio of about 30 to 70 parts by weight with respect to 100 parts by weight of ketones.

  The vulcanized adhesive is prepared as a homogeneous solution by stirring and dissolving so that the solid concentration in the organic solvent is about 3 to 10% by weight.

  When producing an adhesive molded article using the vulcanized adhesive according to the present invention, the adhesive is first coated on a metal, dried at room temperature, and then heat cured at about 100 to 160 ° C. Then, the unvulcanized NBR mixture is joined and pressure-cured at about 170 to 210 ° C. for about 3 to 8 minutes to bond the metal to the NBR. Examples of adhesive moldings in which metal and NBR are well bonded include automotive parts such as oil seals and hub seals.

  The invention will now be described by way of example.

Example 1
High ortho type novolak phenolic resin (Showa Denko 100 parts by weight Shonol BRM-7174H; ortho type content 70 to 80%)
Methacryloxypropyl trimethoxysilane 1 〃
NBR (JSR product N232S; AN content 35% by weight) 28%
Random Novolak Phenolic Resin 50 〃
(Load ink product Chemlock TS 1677-13;
Solid content concentration 40% by weight)
2-butanone 4500 4500
The vulcanized adhesive prepared from each of the above components was applied onto a zinc phosphate-treated mild steel plate, allowed to stand at room temperature for 5 minutes, and then dried at 140 ° C. for 10 minutes.

An unvulcanized NBR-kneaded product having the following composition was joined onto the vulcanized adhesive-coated mild steel plate, and pressure vulcanization was performed at 180 ° C. for 4 minutes to obtain a test piece of an adhesive molded article.
Uncured NBR blend:
NBR (Nippon Zeon product NIPOL DN1042; AN content 34% by weight) 100 parts by weight
FEF carbon black 40 〃
20 powders of silica powder
Zinc oxide 5%
1 stearic acid
Dioctyl phthalate 5 〃
Antiaging agent (2,2,4-trimethyl-1,2-dihydroquinoline) 1 〃
Triallyl isocyanurate (70 wt% concentration) 0.8 〃

Example 2
In Example 1, a vulcanized adhesive composition prepared from the following components was used.
High ortho type novolak phenol resin (BRM-7174H) 100 parts by weight mercaptopropyltrimethoxysilane 3 〃
Random Novolak Phenolic Resin 50 〃
(Chemlock TS 1677-13)
NBR (N232S) 28 〃
2-butanone 4500 4500

Comparative Example 1
In Example 1, a vulcanized adhesive prepared from the following components was used.
100 parts by weight of high ortho type novolac phenolic resin
(Shanord BRM-7174H)
Bisphenol A type epoxy resin (Mitsubishi Chemical Products JSR 1004) 3 bottles
NBR (JSR product N 237; AN content 34% by weight) 21 〃
2-butanone 2980〃

Comparative example 2
In Example 1, a vulcanized adhesive prepared from the following components was used.
High ortho type novolac phenol resin (BRM-7174H) 100 parts by weight bisphenol A type epoxy resin (JSR 1004) 3
Random Novolak Phenolic Resin 52 〃
(Chemlock TS 1677-13)
NBR (N232S) 25 〃
2-butanone 3540〃

Comparative example 3
Random Novolak Phenolic Resin 7 〃
(Chemlock TS 1677-13)
Resole type phenolic resin 3 〃
2-butanone 90〃
Here, as the resol type phenol resin, according to Reference Example 3 described in Patent Document 1, m-cresol-p-cresol mixture and formaldehyde aqueous solution in the presence of barium hydroxide octahydrate 2 at 70 ° C. The one obtained by reacting for time was used.

Comparative example 4
In Comparative Example 1, a vulcanized adhesive was used in which the amount of bisphenol A epoxy resin was changed to 15 parts by weight and the amount of 2-butanone was changed to 3260 parts by weight.

Comparative example 5
In Comparative Example 2, a vulcanized adhesive was used in which the amount of NBR was changed to 37 parts by weight and the amount of 2-butanone was changed to 3820 parts by weight.

In each of the above Examples and Comparative Examples, the presence or absence of contamination of the used mold and the adhesive molded product, and the occurrence rate of micro blisters are determined visually, and the obtained adhesive molded product conforms to JIS K-6301. 90 ° peel test was conducted to measure the rubber remaining area ratio. Further, the adhesion molded product was immersed in pure water, and the percentage area of the remaining rubber after heating at 80 ° C. for 70 hours was measured to evaluate water-resistant adhesion. The evaluation results and the measurement results are shown in the following table. In addition, in the comparative example 4, since it did not function as a vulcanized adhesive, the micro blister generation rate was not able to be measured.


table
Evaluation / Measurement Item Actual 1 Actual 2 Ratio 1 Ratio 2 Ratio 3 Ratio 4 Ratio 5
Contamination Mold None N / A N / A N / A N / A Yes Bonded moldings N / A N / A N / A N / A Yes Small blister rate (%) <3 <3 30 15 40-<3
Rubber remaining area rate (%)
Initial 100 100 100 100 50 0 100
70 80 60 80 20 0 70 after immersion in pure water

Claims (8)

  A vulcanized adhesive composition prepared as an organic solvent solution by adding 0.5 to 5 parts by weight of a silane coupling agent and 15 to 30 parts by weight of uncured NBR per 100 parts by weight of a high ortho type novolac phenol resin.   The vulcanized adhesive composition according to claim 1, wherein a high ortho type novolac phenol resin having an ortho type content of 65% or more calculated from a measurement result by IR is used.   The vulcanized adhesive composition according to claim 1, further comprising 25 parts by weight or less of a random novolac phenol resin or a resol type phenol resin per 100 parts by weight of the high ortho type novolac phenol resin.   The vulcanized adhesive composition according to claim 1, wherein at least one of methacryloxy group-containing silane and mercapto group-containing silane is used as the silane coupling agent.   The vulcanized adhesive composition according to claim 1, wherein an NBR polymer having an acrylonitrile content of 20 to 40% by weight is used.   The vulcanized adhesive composition according to any one of claims 1 to 5, which is used for vulcanization bonding of metal and NBR.   An adhesive molding of metal-NBR vulcanized and bonded using the vulcanized adhesive composition according to claim 6.   The adhesive molded article according to claim 7, which is an oil seal or a hub seal.