JP2003261850A - Vulcanizing adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vulcanizing adhesive composition used for vulcanizing and bonding a metal to a (hydrogenated) nitrile rubber, which is effectively used for the (hydrogenated) nitrile rubber having a nitrile content of 18-48% and prevents decrease in adhesive property, even after being soaked in various coolants such as a chlorofluorocarbon gas, a polyalkylene glycol and water for a long time. <P>SOLUTION: The vulcanizing adhesive composition comprises 100 pts.wt. phenol xylylene resin or phenol biphenyl resin, about 10-1,000 pts.wt. resol phenol resin, 0-1,000 pts.wt. novolac phenol resin, 10-1,000 pts.wt. unvulcanized nitrile rubber and 10-500 pts.wt. chlorinated polyethylene. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vulcanized adhesive composition. More specifically, it relates to a vulcanized adhesive composition that is effectively used for vulcanizing adhesion between a metal and (hydrogenated) nitrile rubber.

[0002]

2. Description of the Related Art Chlorinated rubber type or novolac type phenol resin type adhesives have been used for bonding metal and nitrile rubber (NBR). Of these, the chlorinated rubber adhesive does not have adhesiveness with metals, so it is necessary to separately apply a phenolic undercoat, and the high viscosity makes the coating workability poor and is even better. In order to obtain good adhesiveness, a film thickness of at least 5 μm is required, which is a problem in the case of parts that require dimensional accuracy or fitting parts. On the other hand, in the case of a novolac type phenol resin adhesive, the applicable rubber range is narrow because it adheres only to (hydrogenated) NBR having a nitrile content of 30 to 40%, and since it contains hexamethylenediamine as a curing agent,
There was a problem that gas was generated during drying and baking, and the inside of the dryer was contaminated. Furthermore, all of these adhesives have poor resistance to various refrigerants such as CFCs, water, and PAG (polyalkylene glycol), making it difficult to apply them to refrigerant seals.

In order to solve such a problem, the present applicant has previously proposed a vulcanized adhesive composition containing resol-type phenol resin, unvulcanized NBR, chlorinated polyethylene and the like as essential components (Japanese Patent Laid-Open No. Hei 10 (1999) -242242). 6-306340 and 8-302323). However, when these compositions were used, good adhesion was obtained for (hydrogenated) NBR having a nitrile content of less than 30, but good adhesion was obtained for (hydrogenated) NBR having a nitrile content of 40 or more. Although it does not exhibit the properties and resistance to various refrigerants is superior to the above-mentioned chlorinated rubber-based or phenol-based adhesives, it does not satisfy the currently required level.

[0004]

An object of the present invention is a vulcanized adhesive composition used for vulcanization adhesion of a metal and (hydrogenated) nitrile rubber, which has a nitrile content of 18 to 48% ( It is an object of the present invention to provide a material which is effectively used for (hydrogenated) nitrile rubber and which can suppress deterioration of its adhesiveness even when immersed in various refrigerants such as CFC gas, polyalkylene glycol or water for a long time.

[0005]

The object of the present invention is as follows.
100 parts by weight of phenol xylelin resin or phenol biphenyl resin, about 10-1000 resole type phenol resin
Parts by weight, novolac type phenol resin 0 to 1000 parts by weight,
This is achieved by a vulcanized adhesive composition containing 10 to 1000 parts by weight of unvulcanized nitrile rubber and 10 to 500 parts by weight of chlorinated polyethylene.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION
4-bis (alkoxymethyl) benzene is a polycondensation reaction product of phenol or a phenol derivative having at least one methylol group at the 2- or 4-position, and is actually a commercial product, for example, Meiwa Kasei Product MR-7800. Can be used. In addition, phenol biphenyl resin is 4,4'-bis
(Alkoxymethyl) biphenyl and phenol or its
It is a polycondensation reaction product with a phenol derivative having at least one methylol group at the 2,4 position. In fact, a commercially available product such as Meiwa Kasei product MR-7850 can be used as it is.

As the phenol resin, a resol type phenol resin or a combination of this with a novolac type phenol resin is used. As the resol-type phenol resin, those obtained by subjecting phenols and formaldehyde to a condensation reaction in the presence of an alkaline catalyst are used. At this time, as the phenols, there are two or three substitutable nuclear hydrogens at the o-position and / or the p-position with respect to phenol hydroxyl groups such as phenol, p-cresol, m-cresol, and p-tert-butylphenol. Phenols having atoms or a mixture thereof are used, and as the alkaline catalyst, ammonia, alkali metal hydroxide, magnesium hydroxide or the like is used. Of these resol-type phenolic resins, those produced from a mixture of m-cresol and p-cresol and formaldehyde are preferably used.

As the novolac type phenol resin, a resin obtained by subjecting phenols and formaldehyde to a condensation reaction in the presence of an acidic catalyst is used. At this time, phenol, p-
Cresol, m-cresol, p-tertiary butylphenol and other phenolic hydroxyl groups at the o-position and / or p-position
Phenols having 2 or 3 substitutable nuclear hydrogen atoms or a mixture thereof are used, and as the acidic catalyst, oxalic acid, hydrochloric acid, maleic acid, etc. are used.

The unvulcanized nitrile rubber is a commercially available product having an extremely high nitrile content (nitrile content of 43% or more), a high nitrile content (36 to 42%), and a medium to high nitrile content (31 to 35).
%), Medium nitrile content (25-30% of the same) and low nitrile content (24% or less) of various nitrile rubbers can be optionally used, but those having a medium-high nitrile content are preferably used.

As the chlorinated polyethylene, a highly chlorinated type having a chlorine content of about 60 to 70% is preferably used.

Each of the above components comprises about 10 to 1000 parts by weight of resole type phenol resin, preferably about 20 to 400 parts by weight, and novolac type phenol resin to 100 parts by weight of phenol xylelin resin or phenol biphenyl resin. 0 to 1000 parts by weight, preferably 0 to 100 parts by weight, unvulcanized nitrile rubber is 10 to 1000 parts by weight, preferably 20 to 300 parts by weight.
By weight, chlorinated polyethylene is used in an amount of 10 to 500 parts by weight, preferably 10 to 200 parts by weight.
If the ratio of the resole type phenolic resin or the novolac type phenolic resin to the resole type phenolic resin is higher than this, the adhesion durability to CFCs or water decreases, while if it is used in a lower amount, the adhesiveness to the metal surface in the initial stage becomes low. Will start to decline. Further, when the unvulcanized nitrile rubber is used in a larger proportion than this, the adhesiveness to the metal surface is deteriorated, and the viscosity is increased so much that it hinders the coating work, so that it is used in a smaller proportion. In this case, the compatibility with the nitrile rubber to be adhered is reduced, resulting in poor adhesion. Further, if chlorinated polyethylene is used in a proportion higher than this, the adhesive phase becomes brittle and leads to a decrease in strength, and if it is used in a proportion lower than this, the adhesiveness deteriorates due to a decrease in reactivity with rubber.

A vulcanized adhesive composition containing each of these components as essential components is prepared by using each component as a ketone such as methyl ethyl ketone or methyl isobutyl ketone, or an organic solvent such as an aromatic hydrocarbon such as toluene or xylene, or a mixed solvent. It is prepared as a liquid by dissolving it so that the solid content concentration becomes 3 to 10% by weight.

The vulcanization adhesion using the vulcanization adhesive composition comprising each of the above components is carried out by applying the vulcanization adhesive composition onto a metal such as mild steel, stainless steel, aluminum, aluminum die cast, brass and zinc. After applying this and air-drying at room temperature, it is dried at about 100 to 200 ° C. for about 5 to 30 minutes, and an unvulcanized (hydrogenated) nitrile rubber compound is bonded thereto. The vulcanization temperature of nitrile rubber is about 150
It is carried out by pressure vulcanization at ~ 200 ° C.

[0014]

INDUSTRIAL APPLICABILITY The vulcanized adhesive composition according to the present invention is effectively applied to (hydrogenated) nitrile rubber having a nitrile content of 18 to 48% during vulcanization adhesion of a metal and (hydrogenated) nitrile rubber. In addition, it is possible to suppress the deterioration of the adhesiveness even when it is immersed in CFC gas, polyalkylene glycol, water or the like for a long time.

[0015]

EXAMPLES The present invention will now be described with reference to examples. The unit is parts by weight, and the value in parentheses indicates the solid content weight.

[0016]   Example 1   Phenolxylelin resin 143 (100)     (Meiwa Kasei Product MR-7800 Solid content 70%)   Resol type phenolic resin 67 (40)     (Dainippon Ink and Chemicals product AF-2639L solid content 60%)   Unvulcanized nitrile rubber (N-237, Japanese synthetic rubber product) 40   Chlorinated Polyethylene (Daiso Z-200) 20   Methyl ethyl ketone 1865   Toluene 1865

[0017]   Example 2   Phenolxylelin resin 143 (100)     (Meiwa Kasei Product MR-7800 Solid content 70%)   Cresol-modified novolac phenolic resin 20 (8)     (Dainippon Ink and Chemicals product KA-1053L solid content 40%)   Resol type phenol resin 53 (32)     (Dainippon Ink and Chemicals product AF-2639L solid content 60%)   Unvulcanized nitrile rubber (N-237, Japanese synthetic rubber product) 40   Chlorinated Polyethylene (Daiso Z-200) 20   Methyl ethyl ketone 1862   Toluene 1862

[0018]   Example 3   Phenol biphenyl resin 143 (100)     (Meiwa Kasei Product MR-7851 Solid content 70%)   Resol type phenolic resin 67 (40)     (Dainippon Ink and Chemicals product AF-2639L solid content 60%)   Unvulcanized nitrile rubber (N-237, Japanese synthetic rubber product) 40   Chlorinated Polyethylene (Daiso Z-200) 20   Methyl ethyl ketone 1865   Toluene 1865

[0019]   Example 4   Phenol biphenyl resin 143 (100)     (Meiwa Kasei Product MR-7851 Solid content 70%)   Cresol-modified novolac phenolic resin 20 (8)     (Dainippon Ink and Chemicals product KA-1053L solid content 40%)   Resol type phenol resin 53 (32)     (Dainippon Ink and Chemicals product AF-2639L solid content 60%)   Unvulcanized nitrile rubber (N-237, Japanese synthetic rubber product) 40   Chlorinated Polyethylene (Daiso Z-200) 20   Methyl ethyl ketone 1862   Toluene 1862

[0020]   Comparative Example 1   Resol type phenol resin 167 (100)     (Dainippon Ink and Chemicals product AF-2639L solid content 60%)   Unvulcanized nitrile rubber (N-237, Japanese synthetic rubber product) 28   Chlorinated polyethylene (Daiso Z-200) 14   Methyl ethyl ketone 916   Toluene 916

[0021]   Comparative example 2   Resol type phenol resin 167 (100)     (Dainippon Ink and Chemicals product AF-2639L solid content 60%)   Cresol novolac type epoxy resin 40     (Dainippon Ink and Chemicals product Epicron N695)   Unvulcanized nitrile rubber (N-237, Japanese synthetic rubber product) 40   Chlorinated Polyethylene (Daiso Z-200) 20   Methyl ethyl ketone 1867   Toluene 1867

[0022]   Comparative Example 3   Cresol-modified novolac type phenolic resin 250 (100)     (Dainippon Ink and Chemicals product KA-1053L solid content 40%)   Resol type phenol resin 167 (100)     (Dainippon Ink and Chemicals product AF-2639L solid content 60%)   Unvulcanized nitrile rubber (N-237, Japanese synthetic rubber product) 58   Chlorinated polyethylene (Daiso Z-200) 29   Methyl ethyl ketone 2618   Toluene 2618

Comparative Example 4 Chlorine-based rubber base adhesive (Romfar yeast product Chemlock 252X)

The vulcanized adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 4 consisting of the above components were applied on a zinc phosphate-treated mild steel sheet and allowed to stand at room temperature for 10 minutes. After air-drying, a baking treatment was performed at a baking temperature of 150 ° C. for 10 minutes.

Unvulcanized hydrogenated nitrile rubber compounds (units are parts by weight) of the following compounding examples 1 to 3 were joined to these vulcanized adhesive-bonded mild steel sheets, and pressure was applied at 180 ° C. for 6 minutes. Sulfur was done. An initial adhesion test, a water resistance test, a PAG resistance test and a CFC resistance test were conducted on the obtained vulcanized adhesive. Initial adhesion test: JIS K6256 90 ° peeling test Water resistance test: JIS K6256 90 ° Peeling test piece is immersed in warm water at 80 ° C, and peeling test is carried out 100 hours later PAG resistance: JIS K6256 90 ° peeling test 150 Dip in PAG (polyalkylene glycol) oil at ℃ and perform peel test 100 hours later Freon resistance test: JIS K6256 90 ° Rubber sheet with 0.5 mm thickness is pressed on a metal plate for peeling 90 ° peeling Put the sample obtained by vulcanization molding in a pressure vessel, inject CFC gas (R134a) there, leave the sample for 24 hours in the environment of 40 ° C, take out the sample, heat it in an oven at 150 ° C for 1 hour, Counts the number of foaming starting points due to CFCs generated at the adhesive interface

(Hydrogenated Nitrile Rubber Compounding Examples 1 to 3) Compounding Example 1 Compounding Example 2 Compounding Example 3 HNBR (Zeon Japan Zetpol2020; CN36%) 100 100 HNBR (〃 1020; CN44%) 100 N990 Carbon Black 10 140 SRF Carbon black 51 White carbon (specific surface area 70 m ² / g) 60 Zinc oxide 5 5 5 Stearic acid 0.5 0.5 0.5 Diphenylamine anti-aging agent 1.5 1.5 0.5 (Ouchi emerging product Nocrac CD) Imidazole anti-aging agent 1.5 1.5 2 (Large Nocrac MB) 1,3-di (tertiary butylperoxyisopropyl) 10 10 10 Benzene (concentration 40%) (Nippon Yushi Yushi Peroxymon F40) Adipic acid plasticizer (Asahi Denka RS107) 10 10 2 Vinylsilane Compound (Nippon Unicar product A151) 2 Processing aid (Hüls product Bestenemer 8012) 5 5

The results obtained are shown in Tables 1 to 3 below.

Table 1 (Compounding Example 1) Example Comparative Example 1 2 3 4 1 2 3 4 [Initial adhesion test] Adhesive strength (N / mm) 18.8 18.8 18.6 18.9 8.8 6.5 18.8 18.9 Rubber residual rate (%) 100 100 100 100 10 0 100 100 (Water resistance test) Adhesive strength (N / mm) 18.5 18.5 18.5 18.5--18.5 10.1 Rubber residual rate (%) 100 100 100 100--100 0 (PAG resistance test) Adhesive strength (N / mm) 17.5 17.5 17.5 17.5--17.5 16.5 Rubber residual rate (%) 100 100 100 100--100 80 (CFC resistance test) Number of foams 0 0 0 0--6 20

Table 2 (Compounding Example 2) Example Comparative Example 1 2 3 4 1 2 3 4 [Initial adhesion] Adhesive strength (N / mm) 17.9 18.1 17.9 17.8 17.8 17.7 17.9 17.9 Rubber residual rate (%) 100 100 100 100 100 100 100 100 (Water resistance test) Adhesive strength (N / mm) 17.5 17.3 17.1 17.3 11.1 17.1 17.5 8.5 Rubber residual rate (%) 100 95 100 90 20 70 70 0 (PAG resistance test) Adhesive strength (N / mm ) 17.5 17.5 17.5 17.5 17.3 16.5 17.5 16.5 Rubber residual rate (%) 100 100 100 100 100 90 100 70 (CFC resistance test) Number of foams 0 0 0 0 3 7 5 15

Table 3 (Compounding Example 3) Example Comparative Example 1 2 3 4 1 2 3 4 [Initial adhesion] Adhesive strength (N / mm) 17.1 17.2 17.1 17.3 17.0 17.2 17.2 17.2 Rubber residual rate (%) 100 100 100 100 100 100 100 100 (Water resistance test) Adhesive strength (N / mm) 16.9 16.8 16.9 16.9 14.5 15.9 15 6.5 Rubber residual rate (%) 100 100 100 100 50 80 60 0 (PAG resistance test) Adhesive strength (N / mm) ) 17 16.8 16.9 16.9 16.4 16.9 16.9 12 Rubber residual rate (%) 100 100 100 100 90 100 100 60 (CFC resistance test) Number of foams 0 0 0 0 1 3 6 10

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Claims (4)

[Claims] 1. A phenol xylelin resin or a phenol biphenyl resin 100 parts by weight, a resol type phenol resin 10 to 1000 parts by weight, and a novolac type phenol resin 0-1.
A vulcanized adhesive composition containing 000 parts by weight, 10 to 1000 parts by weight of unvulcanized nitrile rubber, and 10 to 500 parts by weight of chlorinated polyethylene. 2. The method according to claim 1, which is prepared as an organic solvent solution.
The vulcanized adhesive composition described. 3. The vulcanized adhesive composition according to claim 1, which is used for vulcanizing and adhering a metal and a (hydrogenated) nitrile rubber. 4. A metal forming a seal for refrigerant (hydrogenation)
The vulcanized adhesive composition according to claim 3, which is used for vulcanizing adhesion with nitrile rubber.