JP2018009094A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition whose cured product can achieve both excellent transparency and toughness.SOLUTION: The resin composition contains: an acrylic resin (A) which has a unit derived from glycidyl methacrylate and a unit derived from an alkoxyalkyl (meth)acrylate ester and has a weight-average molecular weight of 15,000 or more; an epoxy resin (B); and a curing agent. Both excellent transparency and toughness can be achieved by using the acrylic resin (A) and the epoxy resin (B) in combination.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition.

  For example, epoxy resin compositions are widely used for adhesives used for electronic components such as semiconductors, semiconductor sealing materials for sealing semiconductors, and the like. In addition, in order to compensate for the drawbacks of epoxy resins such as insufficient impact resistance, resin compositions combining acrylic resins and epoxy resins have also been proposed.

  For example, in Patent Document 1, the volume average primary particle diameter and the acetone insoluble content in which the peak temperature and peak height of tan δ at −100 to 0 ° C. in dynamic viscosity measurement are controlled to a specific range are 99 mass% or more. A resin composition containing an acrylic resin and an epoxy resin has been proposed. Patent Document 2 proposes a resin composition containing an acrylic resin having a core having a glass transition temperature of −30 ° C. or lower, a shell having a glass transition temperature of 70 ° C. or higher, and an epoxy resin.

International Publication No. 2010/104055 JP-A-5-65391

  A semiconductor sealing material or an adhesive may be required to have both excellent toughness and transparency. However, it is difficult for the resin compositions as disclosed in Patent Documents 1 and 2 to obtain excellent toughness while maintaining sufficient transparency in the cured product.

  An object of this invention is to provide the resin composition which can make the outstanding transparency and toughness in hardened | cured material compatible.

The present invention has the following configuration.
[1] An acrylic resin (A) having a unit derived from glycidyl methacrylate and a unit derived from a (meth) acrylic acid alkoxyalkyl ester and having a weight average molecular weight of 15,000 or more, an epoxy resin (B), And a resin composition containing a curing agent.

  The resin composition of the present invention can achieve both excellent transparency and toughness in a cured product.

  In this specification, (meth) acrylic acid means acrylic acid or methacrylic acid.

[Resin composition]
The resin composition of the present invention has a unit derived from glycidyl methacrylate (hereinafter referred to as unit (a1)) and a unit derived from (meth) acrylic acid alkoxyalkyl ester (hereinafter referred to as unit (a2)). And the acrylic resin (A) whose weight average molecular weight is 15,000 or more, an epoxy resin (B), and a hardening | curing agent are contained.

(Acrylic resin (A))
The acrylic resin (A) has the unit (a1) and the unit (a2) as essential, and other units other than the unit (a1) and the unit (a2) as necessary (hereinafter referred to as unit (a3)). Have

As the (meth) acrylic acid alkoxyalkyl ester forming the unit (a2), a monomer represented by the following formula (1) is preferable.
R ¹ —CH═CH ₂ —COO— (CH ₂ ) _n —O—R ² (1)
In the formula (1), ^{R 1} is a hydrogen atom or a methyl group, ^{R 2} is a hydrocarbon group having 1 to 6 carbon atoms, n is an integer from 1-2.

The hydrocarbon group for R ² may be an alkyl group or a group having an aromatic ring, and is preferably an alkyl group. When the hydrocarbon group for R ² is an alkyl group, the alkyl group may be linear or branched. The number of carbon atoms in the hydrocarbon group R ² is preferably 1 to 6, more preferably 1 to 2, 1 is particularly preferred.
n is preferably an integer of 1 to 2, and 2 is particularly preferable.

Specific examples of (meth) acrylic acid alkoxyalkyl esters include, for example, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, and the like. It is done. Of these, methoxyethyl (meth) acrylate is particularly preferred as the alkoxyalkyl ester (meth) acrylate.
As a (meth) acrylic-acid alkoxyalkylester, 1 type may be used independently and 2 or more types may be used together.

The monomer for forming the unit (a3) is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, (meth ) Iso-butyl acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, iso-octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, (meth) ) Cyclohexyl acrylate, benzyl (meth) acrylate, and the like. Moreover, carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, maleic anhydride; (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 4-hydroxybutyl, Hydroxyl group-containing monomers such as allyl alcohol; glycidyl group-containing monomers such as glycidyl acrylate and allyl glycidyl ether; amino group-containing monomers such as 2-aminomethyl methacrylate and dimethylaminoethyl (meth) acrylate; acrylamide, methylol (meta ) Amide group-containing monomers such as acrylamide and methoxyethyl (meth) acrylamide; Alkoxy group-containing monomers such as methacryloxypropylmethoxysilane; Acetacetyl group-containing monomers such as acetoacetoxyethyl (meth) acrylate ; Styrene, methyl styrene, aromatic vinyl monomers such as vinyl toluene, vinyl acetate, vinyl chloride, may be used (meth) acrylonitrile.
As a monomer which forms a unit (a3), 1 type may be used independently and 2 or more types may be used together.

  The ratio of the unit (a1) in the acrylic resin (A) is preferably 10 to 99.5% by mass, more preferably 20 to 99% by mass, and more preferably 30 to 90% by mass with respect to all units of the acrylic resin (A). % Is more preferable. If the ratio of the unit (a1) is less than the lower limit value, it becomes difficult to achieve both transparency and toughness because of insufficient curing due to insufficient crosslinking points. When the ratio of the unit (a1) exceeds the upper limit value, the flexibility is insufficient and the toughness becomes poor.

  The proportion of the unit (a2) in the acrylic resin (A) is preferably 0.5 to 90% by mass, more preferably 1 to 80% by mass, and more preferably 10 to 70% by mass with respect to all units of the acrylic resin (A). % Is more preferable. If the proportion of the unit (a2) is less than the lower limit value, the flexibility is insufficient and the toughness becomes poor. When the ratio of the unit (a2) exceeds the upper limit value, it becomes difficult to achieve both transparency and toughness because of insufficient curing due to insufficient crosslinking points.

  The mass ratio a1 / a2 between the unit (a1) and the unit (a2) in the acrylic resin (A) is preferably from 0.11 to 199, more preferably from 0.25 to 99, and even more preferably from 0.42 to 9. If the mass ratio a1 / a2 is less than the lower limit value, it becomes difficult to achieve both transparency and toughness because of insufficient curing due to insufficient crosslinking points. When the mass ratio a1 / a2 exceeds the upper limit value, the flexibility becomes insufficient and the toughness becomes poor.

  30 mass% or more is preferable with respect to all the units of an acrylic resin (A), and, as for the total ratio of the unit (a1) and unit (a2) in acrylic resin (A), 80 mass% or more is more preferable. If the total ratio of the unit (a1) and the unit (a2) is at least the lower limit value, a resin composition that can achieve both transparency and toughness can be easily obtained. The upper limit of the total ratio of the unit (a1) and the unit (a2) is 100% by mass.

The weight average molecular weight of the acrylic resin (A) is 15,000 or more, preferably 20,000 to 1,000,000, and more preferably 100,000 to 600,000. If the weight average molecular weight of the acrylic resin (A) is at least the lower limit value, excellent toughness can be obtained. The acrylic resin (A) having a weight average molecular weight exceeding the upper limit is difficult to synthesize.
As an acrylic resin (A), 1 type may be used independently and 2 or more types may be used together.

A well-known method can be employ | adopted for the manufacturing method of an acrylic resin (A), For example, suspension polymerization, solution polymerization, emulsion polymerization, etc. are mentioned.
As a polymerization initiator used for the polymerization, a known polymerization initiator can be employed, and examples thereof include azobisisobutyronitrile.
A chain transfer agent such as dodecyl mercaptan may be used for the polymerization.

(Epoxy resin (B))
It does not specifically limit as an epoxy resin (B), A well-known epoxy resin can be used.
Examples of the epoxy resin (B) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol E type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, and dicyclopentadiene type epoxy resin. Phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, glycidylamine type epoxy resin and the like.

Examples of the bisphenol A type or bisphenol F type epoxy resin include “JER827” and “JER828” manufactured by Mitsubishi Chemical Corporation. Examples of the phenol novolac type epoxy resin include “EPPN-201” manufactured by Nippon Kayaku Co., Ltd. Examples of the cresol novolac type epoxy resin include “ESCN-190” and “ESCN-195” manufactured by Sumitomo Chemical Co., Ltd .; “EOCN1012”, “EOCN1025” and “EOCN1027” manufactured by Nippon Kayaku Co., Ltd. It is done.
As an epoxy resin (B), 1 type may be used independently and 2 or more types may be used together.

(Curing agent)
The resin composition of the present invention contains a curing agent. As a hardening | curing agent, the well-known hardening | curing agent normally used as a hardening | curing agent of an epoxy resin can be used.
Specific examples of the curing agent include, for example, amine, polyamide, acid anhydride, polysulfide, boron trifluoride, and a compound having two or more phenolic hydroxyl groups in one molecule (for example, bisphenol A, bisphenol F, bisphenol S, etc. ) And various phenol resins.

Examples of commercially available curing agents include "ST11" manufactured by Mitsubishi Chemical Corporation; "Phenolite TD-2090", "Phenolite TD-2131", and "Phenolite LF-4871" manufactured by DIC Corporation. Can be mentioned.
As a hardening | curing agent, 1 type may be used independently and 2 or more types may be used together.

(solvent)
In this invention, in order to improve the handleability of a resin composition, or to adjust a viscosity and storage stability, a solvent can be used as needed. The solvent is not particularly limited, and examples thereof include aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate.
As a solvent, 1 type may be used independently and 2 or more types may be used together.

(Other ingredients)
The resin composition of the present invention may contain components other than the above-described components. Examples of other components include thermosetting resins such as phenol resins and phenoxy resins, thermoplastic resins such as acrylic resins, NBR, SBR, and urethane resins, fine particles, ion scavengers, fillers, photoinitiators, and photosensitizers. Examples include sensitizers, flame retardants, and antioxidants.

  As for content of the acrylic resin (A) in the resin composition of this invention, 5-95 mass% is preferable with respect to the total amount of an acrylic resin (A) and an epoxy resin (B). If content of an acrylic resin (A) is more than a lower limit, the resin composition excellent in toughness will be obtained. When content of an acrylic resin (A) exceeds an upper limit, the effect by an epoxy resin is difficult to be acquired.

  As for content of the epoxy resin (B) in the resin composition of this invention, 5-95 mass% is preferable with respect to the total amount of an acrylic resin (A) and an epoxy resin (B). If content of an epoxy resin (B) is below an upper limit, the resin composition excellent in toughness will be obtained. When content of an epoxy resin (B) is less than a lower limit, the effect by an epoxy resin is hard to be acquired.

  The mass ratio A / B of the acrylic resin (A) to the epoxy resin (B) in the resin composition of the present invention is preferably 0.05 to 19. If mass ratio A / B is more than a lower limit, the resin composition excellent in toughness will be obtained. When mass ratio A / B exceeds an upper limit, the effect by an epoxy resin is difficult to be acquired.

  Although content of the hardening | curing agent in the resin composition of this invention is not specifically limited, With respect to the epoxy group of an acrylic resin (A) and an epoxy resin (B), it is a reactive group (group which reacts with an epoxy group) of a hardening | curing agent. ) Is preferably 0.5 to 1.5 equivalents.

  The method for producing the resin composition of the present invention is not particularly limited. As a method for producing the resin composition of the present invention, for example, after obtaining an acrylic resin solution containing an acrylic resin (A) by solution polymerization or the like, an epoxy resin (B) and a curing agent are mixed into the acrylic resin solution. And a method of volatilizing and curing the solvent.

As described above, in the resin composition of the present invention, the acrylic resin (A) having the unit (a1) and the unit (a2) and having a weight average molecular weight of 15,000 or more, and the epoxy resin (B) And in combination. Thereby, it is possible to achieve both excellent transparency and toughness. Therefore, the resin composition of the present invention is particularly useful as a resin composition for a semiconductor sealing material, a resin composition for an adhesive, or a resin composition for paint.
In addition, the use of the resin composition of this invention is not limited to a semiconductor sealing material, an adhesive material, and a coating material.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by the following description. In the following examples, “part” means “part by mass”.
[Measurement of molecular weight]
About the molecular weight of resin, the weight average molecular weight was measured using the GPC apparatus (HLC-8120 by Tosoh Corporation).

[Synthesis Example 1]
In a separable flask equipped with a stirrer, a reflux condenser, a temperature controller, a dropping pump, and a nitrogen introduction tube, 100 parts of methyl ethyl ketone was placed, and in a nitrogen atmosphere, 70 parts of methoxyethyl acrylate, 30 parts of glycidyl methacrylate and azobisiso A mixture of 1 part of butyronitrile was added dropwise over 4 hours under reflux. Next, after aging under reflux for 8 hours, the mixture was cooled and methyl ethyl ketone was added so that the resin solid content was 50% by mass to obtain an acrylic resin solution containing an acrylic resin having a weight average molecular weight of 150,000.

[Synthesis Examples 2 to 15]
An acrylic resin solution was obtained in the same manner as in Synthesis Example 1 except that the monomer composition was changed as shown in Table 1.

The unit of the monomer composition in Table 1 is part by mass. Moreover, the symbol in Table 1 shows the following meaning.
MEA: methoxyethyl acrylate MEMA: methoxyethyl methacrylate EEMA: ethoxyethyl methacrylate PEA: phenoxyethyl acrylate BA: n-butyl acrylate GMA: glycidyl methacrylate 2-HEMA: 2-hydroxyethyl methacrylate

[Example 1]
The acrylic resin solution obtained in Synthesis Example 1, an epoxy resin (trade name “JER828”, manufactured by Mitsubishi Chemical Corporation), and a curing agent (trade name “ST11”, manufactured by Mitsubishi Chemical Corporation) are combined with acrylic resin: epoxy resin ( (Mass ratio) = 50: 50, and the resin 100 having an epoxy equivalent of 190 was blended so as to be a curing agent 60 to obtain a resin composition.

[Examples 2 to 12, Comparative Examples 1 to 8]
A resin composition was obtained in the same manner as in Example 1 except that the types of acrylic resin and epoxy resin used were changed as shown in Table 2.

[Transparency evaluation]
On a 100 μm thick PET film (trade name “A4300”, manufactured by Toyobo Co., Ltd.), the resin composition of each example was applied so that the film thickness after curing was 50 μm, and the solvent was volatilized. And cured for 3 hours to obtain a test piece. Subsequently, the haze value of the said test piece was measured with the haze meter (Toyo Seiki Seisakusho Co., Ltd. haze guard II).

[Bendability (toughness) evaluation]
The resin composition of each example was cured for 3 hours at 150 ° C. after volatilizing the solvent, and a bending test was performed at a bending speed of 4 mm / min using a test piece processed to a thickness of 4 mm × width of 10 mm × length of 80 mm went. The specimens that were not cracked were designated as “◯ (good)”, and those that were cracked were designated as “x (defective)”.

The evaluation results of each example are shown in Table 2. In addition, the symbol in Table 2 has the following meaning.
JER828: Epoxy resin (trade name “JER828”, manufactured by Mitsubishi Chemical Corporation)
JER807: Epoxy resin (trade name “JER807”, manufactured by Mitsubishi Chemical Corporation)

As shown in Table 2, the resins of Examples 1 to 12 having units (a1) and units (a2) and containing an acrylic resin (A) and an epoxy resin (B) having a weight average molecular weight of 15,000 or more. In the composition, the cured product had a low haze value and excellent transparency, and no bending was observed in the bending test, and the flexibility (toughness) was excellent.
On the other hand, in the resin compositions of Comparative Examples 1 to 8 which do not have either the unit (a1) or the unit (a2) or use an acrylic resin having a weight average molecular weight of less than 15,000, Flexibility (toughness) was not compatible.

Claims (1)

  Acrylic resin (A) having a unit derived from glycidyl methacrylate and a unit derived from (meth) acrylic acid alkoxyalkyl ester, and having a weight average molecular weight of 15,000 or more, epoxy resin (B), and curing agent A resin composition containing: