TWI447196B - Heat-resistant one-solution wet hardening type polycarbonate resin Adhesive composition - Google Patents

Description

Heat-resistant one-liquid moisture-curing polycarbonate resin adhesive composition

The present invention relates to an adhesive composition for a liquid moisture-curable polycarbonate resin which is excellent in heat resistance and adhesion to polycarbonate, in which an adhesive composition for a polycarbonate resin is bonded to each other.

For engineering electronic materials, engineering plastics, PC (polycarbonate) ‧ PS (polystyrene) ‧ PPS (polyphenylene sulfide) ‧ PPO ‧ PET ‧ PBT (polybutylene terephthalate), etc. Polycarbonate is especially widely used from the viewpoint of heat resistance.

In the case of an adhesive for polycarbonate, Patent Document 1 discloses a first component (A) composed of a mixture of a polyfunctional isocyanate compound having an isocyanate group and an organotin compound, and a polyfunctional fluorenyl compound having a mercapto group at the terminal and two An adhesive for a two-component polycarbonate obtained by mixing a second component (B) of a mixture of polycarbonate diols having an OH group at the end. The adhesive described in Patent Document 1 has an initial adhesion property to polycarbonate, but it takes time for work, mixing, and the like because of the two-liquid type.

In the case of a one-component polycarbonate adhesive, Patent Document 2 discloses 1,4-dioxane and 1,1,1-trichloroethane which are a solvent-based adhesive for bonding polycarbonate resin sheets to each other. A solvent-based adhesive for polycarbonate resin sheets obtained by at least one solvent selected from the group consisting of acetic acid, methyl isobutyl ketone and n-butyl alcohol. The adhesive described in Patent Document 2 has excellent adhesion to polycarbonate, but it has a problem in terms of environment and work safety due to the inclusion of a solvent.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] JP-A-2-155979

[Patent Document 2] Japanese Patent Publication No. 4-77590

The present invention is directed to an adhesive composition for a liquid moisture-curable polycarbonate resin which is excellent in heat resistance, adhesion to polycarbonate, and workability.

In order to solve the above problems, the heat-resistant one-liquid moisture-curable polycarbonate resin adhesive composition of the present invention is an adhesive composition for a polycarbonate resin in which a polycarbonate resin is bonded to each other, and is characterized in that it contains a polybutylene. One or more selected from the group consisting of a diol, a modified polytetramethylene glycol, and a polycarbonate polyol, and a urethane prepolymer having an isocyanate group at the terminal obtained by reacting with a polyisocyanate (A) And one or more kinds of curing catalysts (B) selected from the group consisting of a tertiary amine catalyst and a tin catalyst.

The heat-resistant one-liquid moisture-curable polycarbonate resin adhesive composition of the present invention preferably further contains cerium oxide (C).

The amount of the above-mentioned urethane catalyst (A) is preferably 0.01 to 10 parts by mass based on 100 parts by mass of the urethane prepolymer (A).

The adhesive composition of the present invention is excellent in heat resistance and adhesion to polycarbonate, and is used as an adhesive or fixing agent for assembly of electric products or precision machines requiring heat resistance and adhesion to polycarbonate. It has excellent performance and has a low viscosity but excellent long-term preservation stability. Further, the adhesive composition of the present invention is a one-liquid system which is hardened at room temperature by moisture in the air, so that it is excellent in handleability.

[Best Mode for Carrying Out the Invention]

The embodiments of the present invention are described below, but these are merely examples, and various changes that do not depart from the technical scope of the present invention are also covered by the present invention.

The adhesive composition of the present invention is an adhesive composition for a polycarbonate resin in which a polycarbonate resin is bonded to each other, and a urethane prepolymer having an isocyanate group at the terminal obtained by reacting a polyol with a polyisocyanate (A) And one or more kinds of curing catalysts (B) selected from the group consisting of a tertiary amine catalyst and a tin catalyst, and the polyol comprises polytetramethylene glycol, modified polytetramethylene glycol, and polycarbonate. One or more selected from the group consisting of ester polyols.

As the above polytetramethylene glycol, a conventional tetrahydrofuran polymer can be used. The molecular weight of the polytetramethylene glycol is not particularly limited, but it is preferably one having a number average molecular weight of 500 to 5,000, more preferably 500 to 2,000. The above polytetramethylene glycol may be used singly or in combination of two or more kinds.

The modified polytetramethylene glycol is a copolymer of a tetramethylene ether and an alkylene ether, and the alkylene ether preferably has a side chain. The modified polytetramethylene glycol may, for example, be a copolymer of tetrahydrofuran and an alkyl-substituted tetrahydrofuran, a copolymer of tetrahydrofuran and an alkylene oxide, a copolymer of tetrahydrofuran and an alkylene ether having a side chain, or the like. The copolymer of the tetrahydrofuran and the alkyl-substituted tetrahydrofuran is preferably a copolymer of tetrahydrofuran and 3-alkyltetrahydrofuran described in JP-A-63-235320.

The molecular weight of the modified polytetramethylene glycol is not particularly limited, but it is preferably one having a number average molecular weight of 500 to 5,000, more preferably 1,000 to 3,000. The modified polytetramethylene glycol may be used singly or in combination of two or more kinds.

The polycarbonate polyol is preferably a polyol having a structure represented by the following general formula (1).

In the above formula (1), X is a hydrocarbon group, n is a natural number, and R ¹ is a linear alkylene group such as a methylene group, an ethylene group or an n-propylene group, an isopropylidene group, or a sec-butylene group. An alicyclic group such as a branched alkylene group such as a tert-butylene group, a 1,1-cyclohexylene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group, or a 1,4-cyclohexylene group. An arylene group such as a hydrocarbon group, a phenylene group or a naphthylene group; an ether group such as an oxymethylene group or an oxypropylene group; a bisphenol type skeleton such as bisphenol A, bisphenol F or bisphenol S; There are also cases where the repeated structure is expressed more than once. Further, R ¹ may be substituted with various substituents such as a halogen group such as fluorine, chlorine or bromine, a cyano group, a carboxyl group, a sulfonic acid group, a nitro group, a hydroxyl group or an alkoxy group. Further, in addition, R ¹ may be an unsaturated group or a carbonyl group, a carboxyl group, an ether group, a thioether group or a urethane having one or more vinylidene groups at the terminal, both terminals, internal or repeating units. Base, urea base, sulfur urea base, etc. Also, R ¹ may be the same or different, respectively.

The molecular weight of the polycarbonate polyol is not particularly limited, but it is preferably one having a number average molecular weight of 300 to 3,000, more preferably 500 to 2,000. The above polycarbonate polyols may be used singly or in combination of two or more kinds.

The polytetramethylene glycol, the modified polytetramethylene glycol, and the polycarbonate polyol may be used singly or in combination of two or more kinds, and the combination is not particularly limited, and from the viewpoint of handling, the modified polybutylene is used. Alcohol is preferred. When two or more kinds of polyols are used in combination, two or more kinds of polyols can be reacted with polyisocyanate to synthesize a urethane prepolymer (A), or two or more kinds of urethane premixes having different polyol components. The polymer (A) is used.

In the present invention, the polyol component may be blended with other polyols other than the above polytetramethylene glycol, modified polytetramethylene glycol, and polycarbonate polyol. When the polyol is blended with other polyols, the total amount of the polytetramethylene glycol, the modified polytetramethylene glycol, and the polycarbonate polyol is preferably 10% by mass or more based on the total polyol, and more preferably 30% by mass or more.

The other polyol is not particularly limited as long as it contains two or more active hydrogen-containing compounds having an active hydrogen group, and examples thereof include a trifunctional or higher polyhydric alcohol or a polyether polyol such as a diol or a polypropylene glycol (PPG). Polyester polyol, polybutadiene polyol, polyisoprene polyol, polyolefin polyol, polymer polyol, polycaprolactone polyol, polyacrylate polyol, etc., such polyols It can be used alone or in combination of two or more.

The polyisocyanate is not particularly limited, and may be a conventional polyisocyanate compound having two or more isocyanate groups, and examples thereof include diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), and xylene diisocyanate (XDI). In addition to aromatic polyisocyanates such as naphthalene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI) and lysine methyl diisocyanate, hydrogenated diphenylmethane diisocyanate, and An alicyclic polyisocyanate such as phorone diisocyanate, norbornane diisocyanate or hydrogenated toluene diisocyanate. The polyisocyanate is preferably MDI from the viewpoint of cost and reactivity, but it is preferable to use XDI in consideration of discoloration such as yellowing.

The method of reacting the above polyol component with the above polyisocyanate is not particularly limited, and a conventional method can be used. Specifically, a polyol having two or more hydroxyl groups (OH) and a polyisocyanate having two or more isocyanate groups (NCO) are reacted in an excess of an isocyanate group, that is, an NCO/OH equivalent ratio of more than 1, to obtain an end. A urethane prepolymer having an isocyanate group.

The reaction conditions are not particularly limited. For example, the reaction is carried out at 70 to 100 ° C for several hours in a nitrogen or dry air stream at a ratio of NCO / OH equivalent ratio of 1.3 to 10.0, more preferably 1.5 to 5.0. When the NCO/OH equivalent ratio is less than 1.3, the viscosity of the prepolymer becomes high and the workability is problematic, and if it exceeds 10, it may cause discomfort due to foaming.

The conventional urethane prepolymer other than the urethane prepolymer (A) may be further contained in the adhesive composition of the present invention. When combined with other urethane prepolymers, the total amount of the aforementioned urethane prepolymer (A) is 10 relative to the total urethane prepolymer in the adhesive composition of the present invention. The mass% or more is preferably 30% by mass or more.

The aforementioned other urethane prepolymer, specifically, an amino group having an isocyanate group at the terminal obtained by reacting a polyol other than polytetramethylene glycol, modified polytetramethylene glycol, and polycarbonate polyol with an isocyanate compound Formate prepolymer. The other polyol may be an active hydrogen-containing compound having two or more active hydrogen groups, and is not particularly limited. For example, a trifunctional or higher polyhydric alcohol or a diol, a polyether polyol such as polypropylene glycol (PPG), or the like may be used. Ester polyol, polybutadiene polyol, polyisoprene polyol, polyolefin polyol, polymer polyol, polycaprolactone polyol, polyacrylate polyol, etc., such polyols can be Used alone or in combination of two or more.

As the tertiary amine catalyst used in the above curing catalyst (B), conventional tertiary amines such as triethylamine, tripropylamine, triisopropylamine, tributylamine, and triiso are widely used. Butylamine, tri-tert-butylamine, tripentylamine, trihexylamine, trioctylamine, tri-2-ethylhexylamine, methyldi-2-ethylhexylamine, dibutyl 2- a monoamine such as ethylhexylamine, tris(hexadecyl)amine or tribenzylamine; tetramethyl 1,2-diaminoethane, tetramethyl1,3-diaminopropane, tetramethyl a polyamine such as hexamethylenediamine or pentamethyldiethylenetriamine; triethylenediamine; N-ethylmorpholine, bis(morpholinoethyl)ether, bis(2,6 - dimethylmorpholinoethyl)ether, bis(3,5-dimethylmorpholinoethyl)ether, bis(3,6-dimethylmorpholinoethyl)ether, 4-(3 a morpholine compound such as 5-dimethylmorpholino-4'-(3,6-dimethylmorpholino)diethyl ether.

The tin catalyst used in the hardening catalyst (B) can be widely used as a conventional organotin compound, such as a divalent organotin compound such as tin octylate or tin naphthalate; dibutyltin dioctanoate, dibutyltin dilaurate Acid ester, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin distearate, dioctyltin dilaurate, dioctyltin dicochate, dibutyltin oxide, a tetravalent organotin compound such as a reaction product of dibutyltin bis(triethoxyphthalate), dibutyltin oxide and a phthalate ester; a tin-based chelate compound such as dibutyltin bis(acetonitrile) Wait.

The ratio of the above-mentioned curing catalyst (B) is not particularly limited, and it is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 2 parts by mass, based on 100 parts by mass of the urethane prepolymer (A). . The above-mentioned tertiary amine catalyst and tin catalyst may be used singly or in combination of two or more.

The adhesive composition of the present invention preferably contains cerium oxide (C). The cerium oxide (C) may, for example, be smoked sputum, calcined cerium oxide, precipitated cerium oxide, pulverized cerium oxide, or cerium dioxide fused, and fine powder cerium oxide is preferably used.

The ratio of the cerium oxide (C) is not particularly limited, and is preferably 0.5 to 30.0 parts by mass, more preferably 3.0 to 15.0 parts by mass, based on 100 parts by mass of the urethane prepolymer (A). .

In addition to the above components, the adhesive composition of the present invention may be combined with a filler, a plasticizer, a colorant, a discoloration preventive agent, a subsequent imparting agent, a physical property adjuster, a release agent, a slip agent, and a dehydrating agent (storage stability). Various additives such as a modifier, an adhesion-imparting agent, a flow-down preventing agent, an ultraviolet absorber, an antioxidant, a hydrolyzing stabilizer, a flame retardant, a radical polymerization initiator, a diluent such as a high-boiling solvent, and the like.

The foregoing filler is organic or inorganic in various shapes, such as calcium carbonate, magnesium carbonate, zinc carbonate; carbon black; clay; talc; kaolin; diatomaceous earth; zeolite; titanium oxide, quicklime, iron oxide, zinc oxide, cerium oxide. , magnesium oxide; aluminum sulfate; chlorinated vinyl paste resin; glass ball, white sand ball, Saran ball, phenol ball, vinylidene chloride resin ball, etc., inorganic ball, organic ball, etc.; or such fatty acid, fatty acid ester treatment They can be used singly or in combination. Further, an inorganic hollow filler such as a glass ball or a ceria ball, or an organic hollow filler such as a polyvinylidene fluoride or a polyvinylidene fluoride copolymer can be used.

The aforementioned plasticizer may, for example, be dioctyl phthalate (DOP), dibutyl phthalate (DBP), di(dodecyl) phthalate (DLP), Butylbenzyl phthalate (BBP), dioctyl adipate, diisodecyl phthalate, diisodecyl adipate, diisodecyl phthalate Acid ester, trioctyl phosphate, tris(chloroethyl)phosphate, tris(dichloropropyl)phosphate, propylene glycol adipate, butylene glycol adipate, epoxy stearate Base, epoxidized soybean oil, etc., may be used singly or in combination.

The ultraviolet absorber may, for example, be a benzotriazole-based ultraviolet absorber such as 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole or 2-( a triazine-based ultraviolet absorber such as 4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol, or a dibenzoic acid such as octabenzophenone A benzophenone-based ultraviolet absorber or a benzoate-based ultraviolet absorber such as 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate.

The antioxidant may, for example, be a hindered phenol compound or a triazole compound. The hindered phenol-based antioxidant may, for example, be pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] or octadecyl-3-(3,5- Di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4- Hydroxyphenylpropionamide], 3,5-bis(1,1-dimethylethyl)-4-hydroxy C7-C9 side chain alkyl ester of phenylpropanate, 2,4-dimethyl-6- (1-methylpentadecyl)phenol and the like.

The hydrolysis stabilizer, such as an aromatic carbodiimide, especially a carbodiimide monomer having a melting point of about 40 ° C, a carbodiimide low molecular polymer having a melting point of 60 to 90 ° C, and a melting point of 100 to 120 ° C The carbodiimide polymer is preferred. The hydrolyzed stabilizer is preferably used in an amount of 0.01 to 3.0 parts by mass, more preferably 0.1 to 2.0 parts by mass, per 100 parts by mass of the urethane prepolymer (A).

The flame retardant may be a nitrogen-containing compound or an inorganic compound such as an organic halogen compound, a phosphorus compound or an (iso) cyanuric acid derivative compound. Moreover, it is preferable to use a flame retardant which does not contain a halogen from an environmental viewpoint.

The article parts of the present invention can be used to carry out the article parts. The products are electrical products, such as speakers, card projectors, televisions, radios, vending machines, refrigerators, personal computers, CARD-BATTERY, cameras, etc., or cameras, automatic car parts, and precision machines.

[Examples]

The invention is more specifically described by the following examples, but these examples are merely illustrative and not limiting.

(Synthesis Examples 1 to 3) Synthesis of urethane prepolymer (A)

As shown in Table 1, after adding a specific amount of the polyol component to a mixer equipped with a thermometer and dehydrating, a specific amount of the isocyanate component was added, and the reaction was carried out at 70 to 90 ° C for 5 hours in a nitrogen atmosphere to obtain a urethane prepolymer. A1 to A3. The R value (NCO/OH ratio) of the obtained urethane prepolymer is shown in Table 1.

(Comparative Synthesis Examples 1 and 2) Synthesis of urethane prepolymers X and Y

The urethane prepolymers X and Y were obtained in the same manner as in Synthesis Examples 1 to 3 except that the polyol components were changed as shown in Table 1.

The amount of each of the collaterals in Table 1 is expressed in parts by mass, and *1 to *6 are as follows.

*1) Polybutylene glycol: Baotu Valley Chemical Industry Co., Ltd., trade name PTG-2000, molecular weight 2000

*2) Modified polybutanediol: Asahi Kasei (stock) system, trade name PTXG-L1800, molecular weight 1800

*3) Polycarbonate Polyol: Asahi Kasei Co., Ltd., trade name T5652, molecular weight 2000

*4) Polyester polyol: (share) Kuraray, trade name Kuraray Polyol 2010, molecular weight 2000

*5) Polypropylene glycol: Mitsui Chemical Polyurethane (stock), trade name Diol2000, molecular weight 2000

*6) MDI: Japan Polyurethane Industry Co., Ltd.

(Examples 1 to 14)

Mixing with the urethane prepolymer, cerium oxide and diluent under nitrogen flow and at normal temperature, adding a hardening catalyst, stirring and mixing under a nitrogen stream at normal temperature, and obtaining the following Agent composition.

The amount of each of the collaterals in Table 2 is expressed by parts by mass, and the prepolymers A1 to A3 are the urethane prepolymers A1 to A3 synthesized in Synthesis Examples 1 to 3, respectively, and the prepolymers X and Y are Each of the urethane prepolymers X and Y synthesized in Comparative Synthesis Examples 1 and 2, *7 to *10 are as follows.

*7) Amine-based hardening catalyst: bis(morpholinoethyl)ether

*8) Tin-based hardening catalyst: Nitto Chemical Co., Ltd., trade name STNN BL, dioctyltin dico-codate

*9) Cerium Oxide: Japan Aerosil Industrial Co., Ltd., trade name RY200S, smoked 矽

*10) Thinner: JAPAN ENERGY (share), trade name n-alkane N-11

The following test was carried out on the adhesive composition obtained as described above. The results are shown in Table 3.

Adhesion test 1-1) Initial adhesion test

The test was carried out in accordance with JIS K6850. As the adherend, a polycarbonate of 100 × 25 × 3 mm (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name Iupiron sheet NF2000V) was used. The composition of the subsequent composition was applied at a thickness of about 100 μm, and was bonded after 5 minutes of open time. Thereafter, the compound was aged at 23 ° C and 50% RH for one week as an initial adhesion test body. The evaluation criteria are as follows.

○: the strength is 2.0 N/mm ² or more, and the fracture state is the agglutination breaker of the adhesive layer

△: The strength is 1.0 or more, less than 2.0 N/mm ² or the failure state is the interface destruction accompanying the bonding surface.

×: The subsequent strength is less than 1.0 N/mm ²

1-2) Heat resistance adhesion test

After the initial adhesion test body was cooked at a specific temperature (100 ° C or 130 ° C) in a dryer at a specific time shown in Table 3, the test piece was taken out, and the test piece was allowed to stand at 23 ° C, 50% RH for 1 day, and the test was performed every other day. The test method is the same as the initial adhesion test. The strength retention ratio shown by the following formula was calculated, and the heat resistance adhesion evaluation was performed based on the following evaluation criteria.

Strength retention rate (%) = 100 × (heat resistance bonding strength / initial adhesion strength)

◎: Strength retention rate is above 90%

○: Strength retention rate is 70% or more and less than 90%

△: The strength retention rate is 50% or more and less than 70%.

×: strength retention rate is less than 50%

2. Operational test

The viscosity of the adhesive composition at 23 ° C was measured in accordance with the viscosity measurement method of JIS K6833. The viscosity meter used a BS type viscometer, and the viscosity value was evaluated using the viscosity at a rotation number of 10 rpm on the basis of the following evaluation criteria.

◎: Less than 200PaS

○: 200PaS or more, less than 400PaS

△: above 400PaS, less than 600PaS

×: 600 PaS or more

The Ti value (BH type viscosity system 10 rpm viscosity / 1 rpm viscosity) calculated by viscosity measurement was used as an index of broken yarn and evaluated based on the following evaluation criteria.

◎: Ti value of 3.0 or more

○: Ti value of 2.0 or more and less than 3.0

△: Ti value of 1.5 or more, less than 2.0

×: Ti value is less than 1.5

3. Hardening test

The adhesive composition was uniformly applied to a release paper at a temperature of about 3 mm at 23 ° C and 50% RH, and the time until the film formation was measured. The evaluation criteria are as follows.

◎: The time until the film formation is less than 10 minutes

○: The time until film formation is 10 minutes or longer and less than 40 minutes.

△: The time until film formation is 40 minutes or more and less than 80 minutes.

×: The time until film formation is 80 minutes or more

4. Storage stability test

The viscosity measured by the above-mentioned workability test was taken as an initial value, and the sample was transferred to a sealed container, and after heating at 50 ° C for one week, the sample was allowed to cool at 23 ° C for one day, and then the viscosity was measured by the viscosity measurement method of JIS K6833. . The viscosity increase rate (measured value/initial value) was calculated and evaluated based on the following evaluation criteria.

○: The viscosity increase rate is less than 1.5

△: viscosity increase rate of 1.5 or more ~ less than 2.0

×: viscosity increase rate of 2.0 or more

As shown in Table 3, the adhesive composition of the present invention is excellent in initial adhesion and heat resistance adhesion to polycarbonate, and is excellent in workability, hardenability, and storage stability.

(Comparative Examples 1 and 2)

An adhesive composition was obtained in the same manner as in Example 1 except that the composition was changed as shown in Table 4. The obtained adhesive composition was tested in the same manner as in Example 1. The results are shown in Table 5.

In Table 4, the amount of each of the collaterals is expressed in parts by mass, and the prepolymers X and Y are the urethane prepolymers X and Y, *7, *9 synthesized by comparing Comparative Synthesis Examples 1 and 2, respectively. And *10 is the same as Table 2.

(Comparative Example 3)

The test was carried out in the same manner as in Example 1 using a modified fluorenone-based adhesive (trade name: 1530, manufactured by ThreeBond Co., Ltd.). The results are shown in Table 5.

(Comparative Example 4)

The test was carried out in the same manner as in Example 1 using a urethane (polypropylene glycol-MDI)-based adhesive (trade name: UM600V, manufactured by Cemedine Co., Ltd.). The results are shown in Table 5.

Claims (3)

A heat-resistant one-liquid moisture-curable polycarbonate resin adhesive composition which is a polycarbonate resin adhesive composition for bonding polycarbonate resins to each other, characterized by containing polytetramethylene glycol, modified a urethane prepolymer (A) having an isocyanate group at the terminal obtained by reacting one or more selected polyhydric alcohols selected from the group consisting of polytetramethylene glycol and a polycarbonate polyol with a polyisocyanate, and a grade 3 One or more kinds of curing catalysts (B) selected from the group consisting of amine catalysts and tin catalysts. The heat-resistant one-liquid moisture-curable polycarbonate resin adhesive composition according to claim 1, which further contains cerium oxide (C). The heat-resistant one-liquid moisture-curable polycarbonate resin adhesive composition according to claim 1 or 2, wherein the curing agent is blended with 100 parts by mass of the urethane prepolymer (A). (B) 0.01 to 10 parts by mass.