JP2014156522A - Thermosetting composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition containing an aromatic ring-containing alicyclic epoxy compound, and to provide a cured product excellent in heat resistance, thermal yellowing resistance and base material adhesiveness, manufactured by curing the composition by heating.SOLUTION: There is provided a thermosetting composition containing (A) an aromatic ring-containing alicyclic epoxy compound represented by the general formula (1), (B) a cation polymerizable compound other than (A), and (C) a thermal cationic polymerization initiator. In the general formula (1), Ar represents an aromatic skeleton, X represents a bivalent aliphatic hydrocarbon group, Y represents an alicyclic skeleton having an epoxy group, and n is an integer of 2 or more.

Description

  The present invention relates to a thermosetting composition containing an aromatic ring-containing alicyclic epoxy compound and a cured product obtained by curing the composition with heat.

  Epoxy compounds have cured properties such as optical properties, mechanical properties, electrical properties, heat resistance, adhesiveness, moisture resistance, water resistance, chemical resistance, etc. It is widely used as a component material for various applications such as display device applications, mechanical component materials, electrical / electronic component materials, automotive component materials, civil engineering and building materials, molding materials, paints, and adhesives.

  In general, epoxy compounds exhibit various properties by thermosetting using curing agents such as amines, thiols, acid anhydrides, phenols, etc., but many are colored during thermosetting. There is a problem that it cannot be applied to applications requiring transparency. Therefore, a cationic curing technique in which cationic species are generated by ultraviolet rays and an epoxy group is polymerized has been studied.

  However, the ultraviolet curable composition is difficult to apply to a large article that cannot be irradiated with ultraviolet rays or an article having a structure that cannot be irradiated with ultraviolet rays, and there is a problem that an expensive ultraviolet irradiation device is required. It was.

  Therefore, a cationic curing technique in which an epoxy group is polymerized using a thermal cationic polymerization initiator that generates cationic species by heat as a curable composition that does not depend on ultraviolet irradiation has been studied. For example, Patent Document 1 proposes a thermosetting composition comprising a compound having an oxetane ring, an acrylic (co) polymer, and a thermal cationic polymerization initiator. However, in view of transparency, all acrylic (co) polymers are composed of aliphatic groups. As a result, there are problems such as low heat resistance. Further, the adhesion to metal was not satisfactory.

  Patent Document 2 proposes a thermosetting composition comprising an aliphatic alicyclic epoxy compound and a thermal cationic polymerization initiator. Since the cured product using this thermosetting composition is formed by curing an aliphatic alicyclic epoxy compound, sufficient heat resistance cannot be ensured.

  On the other hand, Patent Document 3 proposes a cationically curable composition comprising a compound containing a bisphenol skeleton or a fluorene skeleton and a thermal cationic polymerization initiator, aiming at high heat resistance and a high refractive index. However, since a compound in which an oxygen atom is directly bonded to an aromatic ring is yellowed during heat curing or when the cured product is heated, it cannot be used in applications requiring transparency.

JP 2001-115006 A JP 2006-199790 A Japanese Unexamined Patent Publication No. 2009-179568

  The present invention has been made in view of the above situation, and includes a resin composition containing an aromatic ring-containing alicyclic epoxy compound, and heat resistance and transparency obtained by curing the composition with heat (with heat-resistant yellowing). It is an object of the present invention to provide a cured product having little coloring) and excellent substrate adhesion.

（式中、Ａｒは芳香族骨格を、
Ｘは２価の脂肪族炭化水素基を、
Ｙはエポキシ基を有する脂環族骨格を表し、
ｎは２以上の整数である。） That is, the present invention is represented by the following general formula (1): an aromatic ring-containing alicyclic epoxy compound (A), a cationic polymerizable compound (B) other than the compound (A), and a thermal cation A thermosetting composition comprising a polymerization initiator (C),
The proportion of the aromatic ring-containing alicyclic epoxy compound (A) and the cationically polymerizable compound (B) other than the compound (A) is compound (A) with respect to 100 parts of the aromatic ring-containing alicyclic epoxy compound (A). It relates to a thermosetting composition in which the cationically polymerizable compound (B) other than is 0.1 to 100 parts.
General formula (1)

(Wherein Ar represents an aromatic skeleton,
X represents a divalent aliphatic hydrocarbon group,
Y represents an alicyclic skeleton having an epoxy group,
n is an integer of 2 or more. )

  The present invention also relates to the thermosetting composition described above, wherein Ar is a benzene ring and n is an integer of 2 to 6.

  The present invention also relates to the thermosetting composition as described above, wherein Y is an epoxycyclohexane ring.

  Moreover, this invention relates to the hardened | cured material formed by hardening | curing the said thermosetting composition.

  By using the resin composition containing the aromatic ring-containing alicyclic epoxy compound of the present invention, a cured product excellent in heat resistance, transparency (heat-resistant yellowing and little coloration) and metal plate adhesion by thermosetting. Could be provided.

  The aromatic ring-containing alicyclic epoxy compound (A) of the present invention will be described below.

  The aromatic ring-containing alicyclic epoxy compound (A) of the present invention has a structure represented by the general formula (1). The aromatic skeleton Ar is an n-valent aromatic group obtained by removing n hydrogen atoms directly bonded to the aromatic ring of the aromatic compound. Examples of the aromatic compound include benzene, biphenyl, naphthalene, anthracene, phenanthrene, naphthacene, pentacene, indene, fluorene, diphenylmethane, diphenylethane, diphenylpropane, diphenylsulfone, diphenylfluorene, acetophenone, benzophenone, diphenylether, pyridine, pyrrole, Examples thereof include carbazole, furan, thiophene, and compounds in which some of hydrogen atoms in these aromatic compounds are substituted with alkyl groups, alkoxy groups, alkylthio groups, dialkylamino groups, and the like. In applications where higher transparency is required, benzene and naphthalene, which are not colored, are preferred. Since a compound composed of a plurality of aromatic rings has a concern about fluorescence, benzene is most preferable in consideration of optical applications.

  The divalent hydrocarbon group X is directly bonded to the aromatic ring of the aromatic skeleton Ar. A compound in which a hetero atom such as an oxygen atom or a nitrogen atom is bonded to an aromatic ring is very easily colored, and particularly, it is markedly colored by heat or light. Therefore, it is a feature of the present invention that the atoms bonded to the aromatic ring are limited to hydrogen atoms and carbon atoms. Examples of the divalent hydrocarbon group X include a methylene group, an ethylene group, a propylene group, a butylene group, and an isobutylene group.

  The alicyclic skeleton Y having an epoxy group is obtained by removing one hydrogen atom from a compound in which an epoxy group (oxirane ring) is formed by an adjacent carbon atom and oxygen atom forming the ring structure of an alicyclic compound. It is a monovalent alicyclic group. Examples of the compound in which an epoxy group (oxirane ring) is formed by the adjacent carbon atom and oxygen atom forming the ring structure of the alicyclic compound include epoxycyclohexane, epoxycyclopentane, and epoxynorbornane. Among these, epoxycyclohexane that cures in a short time is preferable.

Preferable specific examples of the compound represented by the general formula (1) include the following compounds.

  The said aromatic ring containing alicyclic epoxy compound (A) is compoundable by the method of Unexamined-Japanese-Patent No. 2012-131989.

  The cationically polymerizable compound (B) other than the compound (A) will be described below.

  Examples of the cationically polymerizable compound (B) other than the compound (A) include aliphatic alicyclic epoxy compounds, glycidyl epoxy compounds, oxetane compounds, and vinyl ether compounds. From the viewpoint of little coloring and curing shrinkage, epoxy compounds and oxetane compounds are preferred.

  The cationically polymerizable compound (B) other than the compound (A) is preferably 0.1 to 100 parts with respect to 100 parts of the aromatic ring-containing alicyclic epoxy compound (A). When the amount is less than 0.1 part, the thermal cationic polymerization initiator is not sufficiently dissolved. When the amount is more than 100 parts, heat resistance and other physical properties are deteriorated.

  The thermal cationic polymerization initiator (C) of the present invention will be described.

  The thermal cationic polymerization initiator is also called a thermal acid generator, a thermal latent curing agent, or a thermal latent cation generator. A compound containing a cationic species is excited by heating, a thermal decomposition reaction occurs, and a substantial function is exhibited as a curing agent that advances thermal curing. The thermal cationic polymerization initiator is different from acid anhydrides, amines, phenol resins and the like that are generally used as curing agents, and even if it is contained in the resin composition, It is possible to provide a one-component resin composition having excellent handling properties without causing an increase in viscosity or gelation.

  Examples of the thermal cationic polymerization initiator (C) include diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, triphenylsulfonium tetrafluoroborate, and tri-p-tolylsulfonium hexafluoro. Phosphate, tri-p-tolylsulfonium trifluoromethanesulfonate, bis (cyclohexylsulfonyl) diazomethane, bis (tert-butylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, triphenylsulfonium trifluoromethanesulfonate, diphenyl-4 -Methylphenylsulfonium trifluoromethanesulfonate, diphenyl-2,4,6-trimethyl Examples include phenylsulfonium-p-toluenesulfonate, diphenyl-p-phenylthiophenylsulfonium hexafluorophosphate, and the like.

As a specific product name of the thermal cationic polymerization initiator (C), for example,
Diazonium salt type: AMERICURE series (American Can), ULTRASET series (Adeka), WPAG series (Wako Pure Chemical Industries)
Iodonium salt type: UVE series (manufactured by General Electric), FC series (manufactured by 3M), UV9310C (manufactured by GE Toshiba Silicone), WPI series (manufactured by Wako Pure Chemical Industries)
Sulfonium salt type: CYRACURE series (Union Carbide), UVI series (General Electric), FC series (3M), CD series (Sartomer), Optmer SP series, Optomer CP series (Adeka) ), Sun Aid SI series (manufactured by Sanshin Chemical Industry Co., Ltd.), CI series (manufactured by Nippon Soda Co., Ltd.), WPAG series (manufactured by Wako Pure Chemical Industries, Ltd.), CPI series (manufactured by San Apro)
However, it is not limited to these.

  The thermal cationic polymerization initiator (C) is a resin component contained in the thermal cationic curable composition (the aromatic ring-containing alicyclic epoxy compound (A) of the present invention and a cationic polymerizable compound (B) other than the compound (A)). The resin component is preferably 0.1 part to 20 parts with respect to 100 parts of the resin component, and if it is less than 0.1 parts, the curing is insufficient, and if it is more than 20 parts, thermal cationic polymerization Initiator-derived coloring and other physical properties are reduced.

  The thermosetting composition of the present invention may further include a sensitizer, a leveling agent, an ultraviolet absorber, a light stabilizer, an antioxidant, an inorganic filler, an adhesion-imparting agent, a non-reactive resin, and the like as necessary. Additives may be added.

  The thermosetting product of the present invention can be obtained by heating and curing the thermosetting composition. This heating temperature is preferably a temperature at which the composition can maintain a molten state. That is, the heating temperature is preferably in the range of 50 ° C to 200 ° C, particularly 80 ° C to 170 ° C.

  The reaction time of the thermosetting reaction varies depending on the composition of the thermosetting product and the conditions of the thermosetting reaction, but is usually 1 minute to 30 hours, preferably 5 minutes to 10 hours, more preferably about 10 minutes to 5 hours.

  Thermosetting reaction consists of a thermosetting composition made of metal such as iron, stainless steel, and aluminum, rubber, plastic (including molded parts and films), glass, concrete, cement mortar, ceramic (films, plates, molded parts, It can be performed by heating after applying to the surface of the base material (including other shaped articles).

  The thermosetting composition may be applied to the substrate surface by a commonly used method such as brush coating, spin coating, spray coating, casting, dipping, roll coating, screen printing, or gravure printing.

  The thermosetting composition containing the aromatic ring-containing alicyclic epoxy compound of the present invention has excellent heat resistance, and has both high transparency (heat yellowing and little coloration) and metal plate adhesion. Therefore, it is suitable for optical fields such as optical discs, IC cards, plastic lenses, plastic optical fibers, optical fiber coating materials and the like that require transparency.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “%” means “% by weight” and “parts” means “parts by weight”.

[Composition Examples 1 to 13]
Table 1 shows an aromatic ring-containing alicyclic epoxy compound (A) and a cationically polymerizable compound (B) other than the compound (A) at 50 ° C. in a 200 cc mayonnaise bottle substituted with an oxygen concentration of 10% or less. It mix | blended in the ratio shown and mixed so that it might become uniform. After this mixture was cooled to room temperature, the thermal cationic polymerization initiator (C) was blended in the ratio shown in Table 1, and sufficiently stirred with an air motor, sufficiently defoamed, and the cation shown in the blending example. A polymerizable composition was prepared.

Table 1

２０２１Ｐ：３，４−オキシランシクロヘキシルメチル−３，４−オキシランシクロヘキサンカルボキシレート（ダイセル化学工業社製）、
ＯＸＴ１０１：３−エチル−３−（ヒドロキシメチル）オキセタン（東亞合成社製）
ＥＸ２１２：１，６−ヘキサンジオールジグリシジルエーテル（ナガセケムテックス社製）
ＪＥＲ８２８：ビスフェノールＡ型オキシラン樹脂（三菱化学社製）
サンエイドＳＩ−１００Ｌ：ベンジルメチルｐ−ヒドロキシフェニルスルホニウムヘキサフルオロアンチモナート／（三新化学工業社製）
を示す。 In Table 1,

2021P: 3,4-oxiranecyclohexylmethyl-3,4-oxiranecyclohexanecarboxylate (manufactured by Daicel Chemical Industries),
OXT101: 3-ethyl-3- (hydroxymethyl) oxetane (manufactured by Toagosei Co., Ltd.)
EX212: 1,6-hexanediol diglycidyl ether (manufactured by Nagase ChemteX Corporation)
JER828: Bisphenol A type oxirane resin (Mitsubishi Chemical Corporation)
Sun-Aid SI-100L: benzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate / (manufactured by Sanshin Chemical Industry Co., Ltd.)
Indicates.

[Example 1]
The thermosetting composition shown in Formulation Example 1 was coated on a metal plate (aluminum plate) using a wire bar coater so as to have a film thickness of 10 to 15 μm to form a thermosetting composition layer. Next, it was cured by heating in an oven at 150 ° C. for 1 hour. The laminate and the cured product were evaluated for heat resistance, heat yellowing resistance, and adhesion.

  For heat resistance, the glass transition temperature (Tg) was measured.

  For heat-resistant yellowing, the color difference before and after putting the cured product at 100 ° C. for 500 hours was compared by ΔY, and less than 0.3 was evaluated as “◯” and 0.3 or more as “×”.

  The adhesion was evaluated by a substrate eye tape method based on JIS K 1990. No peeling was indicated by ○, and peeling was indicated by ×.

[Examples 2 to 9, Comparative Examples 1 to 4]
A sample was prepared and evaluated in the same manner as in Example 1 except that the cationic polymerizable composition was changed as shown in Table 2.

  The evaluation results of Examples 1 to 9 and Comparative Examples 1 to 4 are summarized in Table 2.

Table 2

  As a result, the heat resistance of Comparative Examples 1 and 4 was low. It is considered that sufficient heat resistance could not be ensured because of the aliphatic skeleton.

  Comparative Example 2 resulted in low heat resistance and metal adhesion. This is considered to be due to the fact that it is an aliphatic skeleton and there is no polar group such as an ester bond superior in adhesion.

  Comparative Example 3 resulted in low heat yellowing. A compound in which a hetero atom is directly bonded to an aromatic ring may be more easily colored than a compound in which a carbon atom is directly bonded to an aromatic ring.

  From the above results, the thermosetting composition comprising the aromatic ring-containing alicyclic epoxy compound (A) of the present invention, a cationic polymerizable compound (B) other than the compound (A), and a thermal cationic polymerization initiator (C). It was possible to achieve both heat resistance and transparency (heat-resistant yellowing and less coloring) and metal plate adhesion.

Claims (4)

An aromatic ring-containing alicyclic epoxy compound (A) represented by the following general formula (1), a cationic polymerizable compound (B) other than the compound (A), and a thermal cationic polymerization initiator (C A thermosetting composition comprising:
The proportion of the aromatic ring-containing alicyclic epoxy compound (A) and the cationically polymerizable compound (B) other than the compound (A) is compound (A) with respect to 100 parts of the aromatic ring-containing alicyclic epoxy compound (A). A thermosetting composition in which the cationically polymerizable compound (B) other than is 0.1 to 100 parts.
General formula (1)

(Wherein Ar represents an aromatic skeleton,
X represents a divalent aliphatic hydrocarbon group,
Y represents an alicyclic skeleton having an epoxy group,
n is an integer of 2 or more. )   The thermosetting composition according to claim 1, wherein Ar is a benzene ring, and n is an integer of 2 to 6.   The thermosetting composition according to claim 1 or 2, wherein Y is an epoxycyclohexane ring.   Hardened | cured material formed by hardening | curing the thermosetting composition in any one of Claims 1-3.