JPS6372772A - Adhesive composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. which has excellent bond strength, resistance to water and moisture and bond durability and gives products of good quality, containing a specified polymer rubber, at least one (meth)acrylic acid (ester) monomer and an org. peroxide. CONSTITUTION:1-50pts.wt. polymer rubber (A) having a metal content of not higher than 100ppm and an ion content of not higher than 100ppm [e.g., (isoprene/) butadiene/acrylonitrile copolymer rubber] is blended with 100pts.wt. at least one monomer (B) selected from the group consisting of acrylic acid, methacrylic acid, alkyl acrylates and alkyl methacrylates, 0.1-20pts.wt. org. peroxide (C) such as cumene hydroperoxide and optionally, a curing accelerator (D) such as trimethylthiourea, a compd. (E) having an unsaturated double bond (e.g., an unsaturated alkyd resin), a polymn, inhibitor (F) (e.g., hydroquinone), etc.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention comprises a polymer rubber having excellent adhesive strength, water resistance, and moisture resistance, a (meth)acrylate monomer, and an organic peroxide as essential components. The present invention relates to an adhesive composition that uses adhesive compositions.

(Conventional technology) Epoxy adhesives have traditionally been widely used as structural adhesives, but because they are two-component adhesives, they are troublesome to measure and mix, have a pot life after mixing, take time to harden, etc. Due to problems with epoxy adhesives, acrylic adhesives are being used instead of epoxy adhesives.

Acrylic adhesives generally contain polymer rubber, azilylate monomers, and organic peroxides as essential components.
Although epoxy adhesives do not have the above-mentioned operational problems, their adhesive durability, that is, water resistance and moisture resistance, is inferior to epoxy adhesives, and the development of acrylate adhesives with higher adhesive durability is required. It is requested.

(Problems to be Solved by the Invention) The present invention has been made in view of the above points, and provides an acrylate adhesive containing a polymer rubber that has improved adhesive strength and The object of the present invention is to provide an acrylic adhesive composition with excellent adhesive durability.

(Means for Solving the Problems) Thus, according to the present invention, at least one monomer selected from (1) a polymer rubber, (2) acrylic acid, methacrylic acid, an acrylic acid alkyl ester, and a methacrylic acid alkyl ester color (3) A curable adhesive composition comprising an organic peroxide, wherein a polymer rubber having a metal content of 100 ppm or less and an ion content of 100 PPm or less is used as the polymer rubber. A Hokusho adhesive composition is provided.

The polymer rubber used in the present invention has a metal content of 100 p.
pm or less, and the ion content needs to be 1 o ppm or less. Metal content is 1100pp
If it exceeds 0, the adhesive strength and adhesive durability will be insufficient, preferably Fi80 ppm or less. Moreover, if the ion content exceeds 100 PP'', the adhesive strength and adhesive durability will decrease.It is preferably less than a o ppm.

The polymer rubber used in the present invention is 1,3-butadiene, 2
．． 3-dimethyl 1,3-butadiene, isoprene, 1.
One or more polymers of conjugated diene monomers such as 3-pentadiene and chlorobrennate, conjugated diene monomers and monomers copolymerizable therewith, such as unsaturated nitriles such as acrylonitrile and methacrylonitrile. :Styrene, α-
Aromatic vinyl compounds such as methylstyrene; Unsaturated carboxylic acids and their salts such as acrylic acid, methacrylic acid, itaconic acid, and maleic acid; Esters of the above carboxylic acids such as methyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate. ; alkoxyalkyl esters of the unsaturated carboxylic acids such as methoxyethyl acrylate, ethoxyethyl acrylate, methoxyethoxyethyl acrylate; acrylamide, methacrylamide; N-methylol (meth)acrylamide, N
, N'-dimethylol (meth)acrylamide, more N-substitution of N-ethoxymethyl (meth)acrylamide (amide monomers such as methacoacrylamide; cyanomethyl (meth)acrylate, 2-cyanoethyl (meth)acrylate, 2 - (Meth)acrylic acid cyano-substituted alkyl esters such as ethyl-6-cyatzhexyl (meth)acrylate: allyl glycidyl ether, glycidyl acryl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate.
Copolymer rubber of one or more acrylic esters such as methoxymethyl acrylate and ethoxyethyl acrylate, one or more of these acrylic esters, and acrylic acid, monomethyl maleate, maleic acid, and methacrylic acid copolymerizable with the same. , the (meth)acrylic acid cyano-substituted alkyl ester, vinyl glycidyl ether,
Acrylic acid ester-containing polymer rubbers such as copolymer rubbers with one or more of ethylenically unsaturated monomers such as allyl glycidyl ether, methacrylic glycidyl ether, glycidyl acrylate, glycidyl methacrylate, vinyl acetate, ethylene, propylene, etc. can be mentioned.

The above-mentioned rubber used in the present invention may be a liquid polymer (which may or may not have a functional group such as a carboxyl group, hydroxyl group, or epoxy group at the end of the molecular chain) or may have a high molecular weight. May be a solid polymer ◇Specific polymers include polybutadiene rubber, polyisoprene rubber, polychloroprene rubber, styrene-butadiene copolymer rubber (random and block), styrene-isoprene copolymer rubber (random) and block), butadiene-7crylonitrile copolymer rubber, isoprene-butadiene-7crylonitrile copolymer rubber, isoprene-acrylonitrile copolymer rubber, butadiene-methylacrylate-acrylonitrile copolymer rubber, butadiene-acrylic acid-acrylonitroxyethyl Acrylate-vinyl chloroacetate-acrylonitrile copolymer rubber, butyl acrylate-ethoxyethyl acrylate-hinylnorbornene-acrylonitrile copolymer rubber, butyl acrylate-ethyl acrylate-glycidyl ether copolymer rubber, ethyl acrylate-butyl acrylate-acrylic acid copolymer rubber Examples of polymerized rubber include ethyl V:/-methyl"7/') rate copolymer rubber, ethylene-methyl acrylate-monomethyl maleate copolymer rubber, and ethylene-methyl acrylate-vinyl acetate copolymer rubber. In the present invention, The type of polymer rubber is not particularly limited, and is appropriately selected depending on the intended use and required performance of the adhesive.

In the present invention, the method for producing the rubber is not particularly limited,
Any method may be used as long as it satisfies the above requirements. For example, there is a method of refining a normal emulsion polymerized core copolymer rubber so that the metal content and ion content fall within a predetermined range, a method of obtaining the copolymer rubber by emulsion polymerization by reducing the amount of emulsifier as much as possible, and a method that uses neither the emulsifier nor the solvent. A method of obtaining the copolymer rubber by bulk polymerization without using it, a method of using solution polymerization, etc. are shown.

The amount of the polymer rubber used in the adhesive composition of the present invention is 1 to 50 parts by weight per 100 parts by weight of the second component monomer described later.
] i, i is 1 part, and if it is less than 1 part by weight, the viscosity of the adhesive composition will be low, the adhesive after curing will be glassy, and the adhesive strength will be insufficient.

Further, if the amount exceeds 50 parts by weight, the viscosity of the adhesive composition becomes extremely high, making it difficult to perform bonding work. Preferably it is 5 to 30 parts by weight.

The second component of the adhesive composition of the present invention is one or more monomers taken from acrylic acid, methacrylic acid, acrylic acid alkyl esters, and methacrylic acid alkyl esters.

Examples of acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, inbutyl acrylate, tert-butyl acrylate, octyl acrylate, etc., but preferably the number of carbon atoms in the alkyl group is 1 to 4 acrylic acid alkyl esters.

Examples of methacrylic acid alkyl esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate,
Examples include butyl methacrylate, inbutyl methacrylate, tert-butyl methacrylate, octyl methacrylate, etc., but preferably the alkyl group has 1 to 4 carbon atoms.
methacrylic acid alkyl ester.

Examples of the third component organic peroxide include t-butyl, cumene,
Hydroperoxides such as di-isoglobilbenzene, p-menthane, 2,5-dimethylhexane-2,5-di, 1.1.5°3-tetramethylbutyl, di-t
-Butyl peroxide, dicumyl peroxide, α
, dialkyl peroxides such as α′-bis(t-butylperoxyisoglopyl)benzene, diacylperoxides such as acetyl peroxide, isobutyl peroxide, benzoyl peroxide, lauroyl peroxide, and 2,4-dichlorobenzoyl peroxide. oxide, ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, acetylacetone peroxide, 1,1-bis(t
-butylperoxy)-3,3,5-trimethylcyclohexane, peroxyketals such as 2,2-bis(1-butylperoxy)octane, diisopropylperoxydicarbonate, di-2-ethoxyethylperoxydicarbonate, etc. peroxydicarbonate, t
-butyl peroxyisobutyrate, t-butyl peroxyhybarate, cumyl peroxy neodecanoate,
Examples include peroxy esters such as t-butyl peroxylaurate, and preferred is at least one selected from hydroperoxide, diacyl peroxide, peroxyketal, and peroxydicarbonate.

The amount of these organic peroxides used is 10% of the second component monomer.
It is usually 0.1 to 20 parts by weight per 0 parts by weight.

If the amount is less than 0.1 part by weight, curing will be insufficient and adhesive strength will decrease. If the amount exceeds 20 parts by weight, the storage stability of the adhesive composition will decrease. Preferably from 0.1 to 10 parts by weight ◇ In the adhesive composition of the present invention, it is desirable to use a curing accelerator together with the above-mentioned essential components.

The curing accelerator used is N,N-dimethylaniline, N,N-diethylaniline, N,N-dimethyltoluidine, N,N-diethyl from the viewpoint of achieving a practical curing time and adhesive strength. Tertiary amines such as toluidine and triethylamine, polyamines such as diethylenetriamine, triethylenetetramine, and pentaethylenehexamine, thiourea, trimethylthiourea, tetramethylthiourea, diptylthiourea, dilaurylthiourea,
Thioamide compounds such as acetylthiourea, ethylenethiourea, diphenylthiourea, ditolylthiourea, mercaptobenzimidazole, metal salts such as cobalt naphthenate, manganese naphthenate, iron oleate,
Examples include organometallic complexes such as cobalt acetylacetonate and dipyridyl iron, reducing organic compounds such as L-ascorbic acid, D-1so-ascorbic acid, and gallic acid, and triazinethiols such as triazine trithiol and dibutylaminotriazine dithiol. At least one type selected from these can be used. Preferably, at least one selected from tertiary amines, polyamines, thioamide compounds, and reducing organic compounds.
It is a seed. In addition, the amount used is preferably 0.1 to 20 parts by weight per 100 parts by weight of the second component monomer in the adhesive composition, and if it is less than 0.1 part by weight, it will take a practical curing time. It is difficult to obtain, and if it exceeds 20 parts by weight, the adhesive strength will decrease significantly.

In the present invention, in addition to the above, compounds having unsaturated double bonds can be added for the purpose of modifying various properties, viscosity, curing time, etc. of the adhesive. Compounds include glycidyl acrylate, glycidyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, dimethylaminoether acrylate, dimethylaminoether methacrylate, diethylaminoether acrylate, Acrylic acid or methacrylic acid esters such as diethylaminoethyl methacrylate, ethoxyethyl acrylate, and ethoxyethyl methacrylate; unsaturated amides such as acrylamide, methacrylamide, N,N-dialkyl acrylamide, N,N-dialkylmethacrylamide; Polar compounds such as unsaturated nitrites such as acrylonitrile and methacrylaterile, N-vinyl compounds such as N-vinylpyrrolidone and N-vinylcarbazole, vinyl acetate, ethyl vinyl ether, vinyl chloride, vinylidene chloride, methyl vinyl ketone, and methyl impropenyl ketone. Monomers, styrene, α-methylstyrene,
Styrene derivatives such as methoxystyrene and chlorstyrene, ethylene glycol diacrylate (or methacrylate), tetraethylene glycol diacrylate (or methacrylate), trimethylolpropane triacrylate (t or methacrylate), acrylic acid (or methacrylic acid) ), glycols, and polybasic acids; polyester acrylates (or methacrylates) obtained from the reaction of acrylic acid (or methacrylic acid) with epoxy compounds; epoxy acrylates (also methacrylates); polybasic acids. Amide acrylate (or methacrylate) obtained by reacting with amino alcohol and then acrylic acid (' or methacrylic acid), urethane obtained by reacting hydroxyalkyl acrylate (or methacrylate) with a polyisocyanate compound. Examples include acrylic acid (or methacrylic acid) esters such as acrylate (or methacrylate), monomers having multiple unsaturated double bonds such as divinylbenzene, divinyl ether, and diallyl phthalate.

Further, in order to improve the storage stability of the adhesive, a small amount of a polymerization inhibitor may be added to the composition. These inhibitors include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, p-benzoquinone, tolquinone, xyquinone, catechol, t-butylcatechol, 2-t-phthyl-4-hydroxyanisole,
Commonly known polymerization inhibitors such as 2.6-di-t-butyl-p-cresol, picric acid, phenothiazine, hydroxydiphenylamine, and diphenylpicrylhydrazyl can be used. The amount of these polymerization inhibitors is suitably 2Jl or less, but exceeds 0.2% by weight, based on the total amount of the second component monomer and other monomers added as necessary in the adhesive composition. and the adhesive strength decreases,
Curing time is significantly delayed.

Furthermore, various fillers, gelling agents, plasticizers, colorants, etc. can be added to the adhesive composition of the present invention depending on the purpose of use.

The adhesive composition of the present invention can be prepared as a one-component adhesive by mixing the above-mentioned components, or by dividing the mixture of polymer rubber and (meth)acrylate monomer into two parts, and one part has an organic It is used as a two-part adhesive containing an oxide, etc., and a curing accelerator. The adhesive is cured according to conventional methods.

By using the adhesive composition of the present invention, excellent adhesive strength and adhesive durability such as water resistance and moisture resistance can be obtained, making it possible to manufacture high-quality products in various fields.

(Example) The present invention will be described in more detail with reference to Examples below. Note that parts and parts in Examples and Comparative Examples are based on weight unless otherwise specified.

Examples 1 to 4 Acrylonitrile-butadiene copolymer rubber (NBR) with a bound acrylonitrile content of 33% produced by bulk polymerization method, solution polymerization method, and emulsion polymerization method and commercially available NBR (Nippon Zeon Co., Ltd. N1pol 1042, bound acrylonitrile content 33%) %) was dissolved and reprecipitated three times to prepare a total of four NBRs.

Using each of these NBHs and according to the adhesive formulation listed in Table 1, an adhesive composition consisting of two liquids, liquid A containing an organic peroxide and liquid B containing a decomposition accelerator for organic peroxides, was prepared. was prepared.

The preparation method is to add methyl methacrylate (MMA), NBR, unsaturated alkyd resins, etc. to a 2-piece glass flask, stir and mix at room temperature for 24 hours to create a homogeneous solution, and then add organic peroxide. , additives, etc. were added, and the mixture was further stirred for 1 hour.

Table 1 Note) (1) Represents methyl methacrylate (2) Polyset 548 manufactured by Hitachi Chemical Co., Ltd. (3) Represents cumene hydroperoxide (4) Represents hydroquinone Liquid A/Liquid B - 1/1 (weight ratio ) and an adhesive durability test was conducted. Mild steel plates were used as adherends, and an adhesive was applied to a thickness of one inch on one of the mild steel plates, and the other steel plate was stacked on top of the other plate and left at room temperature for 20 minutes. Tensile shear adhesive strength: JL8 K6
Evaluation was made in accordance with 854 at a tensile speed of 5 m5Z minutes. The results are shown in Table 2 along with the properties of NBR.The metal content listed in Table 2 was measured using an atomic absorption spectrometer (model 280- manufactured by Hitachi, Ltd.).
50), and the contained metals are Li, Na,
, Mg, Ca.

Assuming A/, an, Cu, Zn, and Fe, the content of each of these metals was measured and expressed as the total amount of each measured value.

・Ion content was determined by ion chromatography (Dionex Model 20001 was used. Column was HP Engineering C.
-A31~5 and! '1 Use PIC-O81-2. )
It is expressed as the total amount of each ion amount determined by.

Comparative Examples 1 to 4 Two types of commercially available NBR (N1po11032 and N1po1104 manufactured by Nippon Zeon Co., Ltd.) were used in place of NBH in Examples 1 to 4.
2. The amount of bound acrylonitrile is 33 in both cases)
and purified N1pol 1042 and unpurified N1po
Adhesive compositions were produced in the same manner as in Examples 1 to 4 using two types of NBR prepared by mixing with 1042 , and performance evaluations were performed in exactly the same manner as in Examples 1 to 4. The measurement results are shown in Table 2 along with the properties of each NBR.

Examples 5-9. Comparative Example 5 A ternary copolymer rubber of butadiene/methacrylic acid/acrylonitrile (abbreviated as 5515/40%N15XR(I)) was prepared by a bulk polymerization method.A ternary copolymer rubber of the same composition was prepared by a normal emulsion polymerization method. An adhesive composition (abbreviated as NBxR (If)) was prepared using these polymer rubbers, and performance evaluation was performed.

Table 5 shows the properties of the polymer rubber, and Table 4 shows the adhesive formulation and performance evaluation results.

Table 3 r Examples 10-13. Comparative Example 6 Commercially available highly saturated NBR (manufactured by Nippon Zeon Co., Ltd., ZetpO'
11020, bonded nitrile 1145 width) was purified by repeating dissolution and reprecipitation three times (abbreviated as Nl!: MCI)).

As a comparative example, Zetpol 1020 (NIM (IF)
) was used. Adhesive compositions were manufactured using these polymer rubbers and their performance was evaluated. Table 5 shows the properties of the polymer rubber, and Table 6 shows the adhesive formulation and performance evaluation results.

Table 5 Example 14. Comparative Example 7 A styrene-butadiene copolymer rubber (8BR) having a bound styrene content of 23.5% was prepared by bulk polymerization. As a comparative example, commercially available styrene-butadiene rubber (N1pol 1502 manufactured by Nippon Zeon Co., Ltd., amount of bound styrene 23.5
1), adhesive compositions were produced in the same manner as in Examples 1 to 4, and their performance was evaluated.

The measurement results are shown in Table 7 together with the properties of SDR.

Table 7 Example 15. Comparative Example 8 Commercially available polybutadiene rubber (N1pol manufactured by Nippon Zeon Co., Ltd.
BR1220) was purified by repeating dissolution and reprecipitation three times. As a comparative example, adhesive compositions were produced in the same manner as in Examples 1 to 4 using N1pol BR1220, and performance evaluations were performed in the same manner. The measurement results are shown in Table 8 along with the properties of the rubber.

Table 8 Examples 16 to 17 A terpolymer rubber (abbreviated as MAR (I)) of ethyl acrylate/butyl acrylate/acrylonitrile (50/40/10% by weight) was prepared by a bulk polymerization method. A ternary copolymer rubber having the same composition as XAR (1) was prepared by a conventional emulsion polymerization method (abbreviated as XAR (IF)), and purified by repeating dissolution and reprecipitation three times. Adhesive compositions were produced in the same manner as in Examples 1 to 4 using these two types of polymer rubbers, and their performance was evaluated. The measurement results are shown in Table 9 together with the properties of the rubber.

Comparative Examples 9 to 10 Examples 9 to 100 The same procedure was carried out using commercially available acrylic rubber (N1pol AR51 manufactured by Nippon Zeon Co., Ltd.) and X A R (If) prepared in Examples 9 to 10 instead of the polymer rubber. An adhesive was manufactured and its performance evaluated.

The measurement results are shown in Table 9 together with the properties of the rubber used.

Table 9

Claims (1)

[Claims] (1) Polymer rubber, (2) acrylic acid, methacrylic acid,
At least one monomer selected from acrylic acid alkyl ester and methacrylic acid alkyl ester and (3
) A curable adhesive composition containing an organic peroxide, wherein a polymer rubber having a metal content of 100 ppm or less and an ion content of 100 ppm or less is used as the polymer rubber.