JP4846886B2 - Flame retardant epoxy resin composition - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an environment-friendly flame retardant epoxy resin composition used for electric / electronic parts.
[0002]
[Prior art]
Epoxy resins are excellent in heat resistance, electrical properties, mechanical properties, etc., and are therefore used for various electrical and electronic components.
In general, electrical and electronic parts are required to have flame retardancy. To achieve this, epoxy resin compositions used for electrical and electronic parts include halogen-containing epoxy resins and flame retardants as epoxy resins. Many antimony-containing compounds are used as the material.
[0003]
[Problems to be solved by the invention]
In recent years, with increasing awareness of environmental issues, the demand for reducing substances that pollute the environment has become very strong.
As a result, halogens are incinerated, dioxin-related substances are suspected to be generated depending on the incineration conditions, and antimony is suspected to be carcinogenic. It has become.
As a substitute for halogen and antimony, there is a move to use phosphorus-based flame retardants, but there is a suspicion that environmental pollutants are generated during incineration,
An environmentally friendly flame retardant epoxy resin composition that does not contain halogen, antimony, and phosphorus is desired.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present inventors have studied the thermal stability of an epoxy resin and a curing agent, and by combining a specific epoxy resin and a curing agent, an epoxy resin composition having excellent flame retardancy and no practical problem. It was found that a product can be obtained, and the present invention has been achieved.
[0005]
That is, the present invention is 1.1) epoxy resin (excluding epoxy resin containing more than 0.2% by weight of halogen or phosphorus)
2) Curing agents (except for curing agents containing halogen or phosphorus)
3) An epoxy resin composition that requires an accelerator, and the cured product that has been cured and ground to 100-200 mesh is 2 from the low temperature side of the weight loss curve in thermogravimetric analysis in nitrogen. A flame retardant epoxy resin composition used for electrical and electronic parts, wherein the weight loss rate up to the second inflection point is 50% or less,
2. In the thermogravimetric analysis of the cured product pulverized to 100 to 200 mesh in air, the ratio of weight reduction to the maximum exothermic peak is 65% or less. The epoxy resin composition according to the description,
3. The temperature of the second inflection point from the low temperature side of the weight loss curve in the thermogravimetric analysis in nitrogen of a cured product pulverized to 100 to 200 mesh is 400 ° C. or higher. Or 2. The epoxy resin composition according to the description,
4. The rising temperature to the maximum peak in the thermogravimetric analysis in air of the cured product pulverized to 100 to 200 mesh is 450 ° C. or higher. ~ 3. The epoxy resin composition according to any one of
5.1. ~ 4. The hardened | cured material formed by hardening | curing the epoxy resin composition of any one of these.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As the epoxy resin used in the present invention, any epoxy resin that is usually used for electric / electronic parts and does not contain more than 0.2% by weight of halogen or phosphorus may be used. Specific examples of epoxy resins that can be used include bisphenol A, tetramethylbisphenol F, bisphenol F, bisphenol S, bisphenol K, biphenol, tetramethylbiphenol, hydroquinone, methylhydroquinone, dimethylhydroquinone, trimethylhydroquinone, di-ter. Glycidyl compounds such as butylhydroquinone, resorcinol, methylresorcinol, catechol, methylcatechol, dihydroxynaphthalene, dihydroxymethylnaphthalene, dihydroxydimethylnaphthalene, phenols, or condensates of naphthols and aldehydes, phenols or naphthols and xylylene Examples thereof include a condensate with glycol, a condensate of phenols or naphthols with bismethoxymethylbiphenyl, a condensate of phenols with isopropenylacetophenone, or a glycidylation product such as a reaction product of phenols with dicyclopentadiene.
These can be obtained by known methods.
[0007]
Examples of the phenols include phenol, cresol, xylenol, butylphenol, amylphenol, nonylphenol, catechol, resorcinol, methylresorcinol, hydroquinone, phenylphenol, bisphenol A, bisphenol F, bisphenol K, bisphenol S, biphenol, tetramethylbiphenol, etc. Is exemplified.
[0008]
Examples of naphthols include 1-naphthol, 2-naphthol, dihydroxynaphthalene, dihydroxymethylnaphthalene, dihydroxydimethylnaphthalene, trihydroxynaphthalene and the like.
[0009]
Furthermore, as aldehydes, formaldehyde, acetaldehyde, propyl aldehyde, butyraldehyde, valeraldehyde, capronaldehyde, benzaldehyde, chlorbenzaldehyde, bromobenzaldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipine aldehyde, pimelin aldehyde, Examples are sebacinaldehyde, acrolein, crotonaldehyde, salicylaldehyde, phthalaldehyde, hydroxybenzaldehyde and the like.
The epoxy resin used in the present invention is exemplified above, but it may be combined with a cured product that is used for electrical / electronic components, and the cured product only needs to satisfy the above conditions. Several types are used in combination.
[0010]
Furthermore, since it is used for electricity and electronics, those having a low hydrolyzable chlorine concentration are preferred. For example, hydrolyzable chlorine is 0.2 wt% or less, preferably 0.15 wt% or less, as defined by the elimination chlorine when epoxy resin is dissolved in dioxane and treated with 1N KOH for 30 minutes under reflux. The epoxy resin is preferable.
[0011]
Any curing agent may be used as long as it is used for electric / electronic parts. Specifically, bisphenol A, tetramethylbisphenol F, bisphenol F, bisphenol S, bisphenol K, biphenol, tetramethylbiphenol, hydroquinone, methylhydroquinone, Dimethyl hydroquinone, trimethyl hydroquinone, di-ter. Glycidyl compounds such as butylhydroquinone, resorcinol, methylresorcinol, catechol, methylcatechol, dihydroxynaphthalene, dihydroxymethylnaphthalene, dihydroxydimethylnaphthalene, phenols, or condensates of naphthols and aldehydes, phenols or naphthols and xylylene Examples include condensates of glycols, condensates of phenols or naphthols and bismethoxymethylbiphenyl, condensates of phenols and isopropenylacetophenone, and reactants of phenols and dicyclopentadiene.
Although the hardening | curing agent used for this invention is illustrated above, it is used for an electrical / electronic component, it should combine with an epoxy resin and the hardened | cured material should just satisfy the said conditions.
These curing agents are used alone or in combination. Moreover, you may use together with other hardening | curing agents, such as an amine type and an acid anhydride type.
[0012]
As the above-mentioned phenols, phenol, cresol, xylenol, butylphenol, amylphenol, nonylphenol, catechol, resorcinol, methylresorcinol, hydroquinone, phenylphenol, bisphenol A, bisphenol F, bisphenol K, bisphenol S, biphenol, tetramethylbiphenol Etc. are exemplified.
[0013]
Examples of naphthols include 1-naphthol, 2-naphthol, dihydroxynaphthalene, dihydroxymethylnaphthalene, dihydroxydimethylnaphthalene, trihydroxynaphthalene and the like.
[0014]
Furthermore, as aldehydes, formaldehyde, acetaldehyde, propyl aldehyde, butyraldehyde, valeraldehyde, capronaldehyde, benzaldehyde, chlorbenzaldehyde, bromobenzaldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipine aldehyde, pimelin aldehyde, Examples are sebacinaldehyde, acrolein, crotonaldehyde, salicylaldehyde, phthalaldehyde, hydroxybenzaldehyde and the like.
[0015]
The usage-amount of a hardening | curing agent is 0.3-1.5 equivalent normally with respect to an epoxy group, Preferably it is 0.5-1.3 equivalent. When the amount is 0.3 equivalent or less, the number of unreacted epoxy groups increases. When the amount is 1.5 equivalents or more, the amount of the unreacted curing agent increases, which is not preferable because the thermal and mechanical properties are lowered.
[0016]
Examples of the curing accelerator include phosphines such as triphenylphosphine and bis (methoxyphenyl) phenylphosphine, imidazoles such as 2methylimidazole and 2ethyl4methylimidazole, trisdimethylaminomethylphenol, diazabicycloundecene and the like. And tertiary amines.
In addition, although the thing containing phosphorus is contained in a hardening accelerator, since the usage-amount of a hardening accelerator is very small compared with another component, it does not have a bad influence on an environment.
[0017]
The usage-amount of a hardening accelerator is 0.2-6.0 weight part normally per 100 weight part of epoxy resins, Preferably, it is 0.4-4.0 weight part.
[0018]
The epoxy resin composition of this invention can knead | mix and mix an epoxy resin, a hardening | curing agent, and a hardening accelerator uniformly with a roll, a kneader, etc. The epoxy resin composition of this invention selects the essential component so that the hardened | cured material obtained by hardening over 2 to 6 hours at 100-200 degreeC may satisfy | fill the following conditions. The conditions that the cured product of the epoxy resin of the present invention must have will be described below. In addition, although the epoxy resin composition of the present invention can contain an inorganic filler or the like as an optional component, in the case of the properties possessed by the epoxy resin composition of the present invention (weight reduction ratio in thermogravimetric analysis described below) Measure without any optional components. First, the cured product is pulverized to 100 to 200 mesh and subjected to thermogravimetric analysis in air and nitrogen. If the particle size of the cured product is too large, it is difficult to separate the exothermic peak in the air into two, and the heat conduction is very low, so reproducibility is lacking. In addition, it is difficult to reduce the particle size in a particularly flexible sample. In thermogravimetric analysis in nitrogen, a sudden weight loss occurs over the first inflection point from a gradual weight loss, and a gradual weight loss from the second inflection point to a weight loss after the first inflection point. Is observed. From the first inflection point, the second inflection point and the second inflection point are linearly approximated, and the weight decrease at the intersection is defined as the weight decrease at the second inflection point. A thing which is 50% or less, preferably 45% or less has a very short combustion duration in the vertical combustion test and has high flame retardancy. This is presumably because the weight loss from the first inflection point to the second inflection point in the thermogravimetric analysis in nitrogen is a dominant factor for continuing combustion. When the weight loss exceeds 50%, the combustion duration time becomes long, which is not preferable as a flame retardant resin composition.
[0019]
When a weight analysis of the same sample is performed in the air, first, an exothermic peak and a weight decrease estimated to be partial oxidative decomposition of a side chain or an ether bond are observed. Next, a rapid weight loss and a maximum exothermic peak presumed that the main chain has undergone rapid oxidative decomposition are observed on the higher temperature side. In the cured product of the epoxy resin composition of the present invention, the weight loss at the second inflection point in nitrogen is 50% or less, and the weight reduction ratio to the maximum exothermic peak in air is 65% or less. Preferably, it is 60% or less. If the rate of weight loss exceeds 65%, thermal decomposition in an oxidizing atmosphere is too large, which is not preferable.
[0020]
The temperature at the second inflection point in thermogravimetric analysis in nitrogen is 400 ° C. or higher, preferably 420 ° C. or higher. If it is less than 400 ° C., the thermal stability is insufficient, gas generation due to thermal decomposition is likely to occur, and combustion is difficult to stop, which is not preferable.
[0021]
In thermogravimetric analysis in air, the intersection of the lowest point between the first peak and the maximum peak, the tangent line between the horizontal axis and the parallel line, and the approximate straight line of the curve up to the maximum peak is defined as the rising temperature of the maximum peak. The rising temperature to the maximum peak is 450 ° C. or higher, preferably 460 ° C. or higher. When the temperature is 450 ° C. or lower, gas is likely to be generated by oxidative decomposition, which is not preferable.
[0022]
Furthermore, the epoxy resin composition of this invention can add an inorganic filler, a pigment, a mold release agent, a silane coupling agent, a softening agent, etc. as needed.
In particular, the addition of an incombustible inorganic filler has the effect of further improving the flame retardancy of the composition of the present invention, and in terms of flame retardancy, as long as there is no hindrance to workability and physical properties after curing, It is desirable to add a large amount.
Examples of the noncombustible inorganic filler include hydroxides such as aluminum hydroxide, magnesium hydroxide, and iron hydroxide, zinc stannate, silica, alumina, calcium carbonate, aluminum nitride, silicon nitride, and the like.
An inorganic filler is used as needed in the ratio which occupies 30 to 95 weight% in the epoxy resin composition of this invention.
[0023]
The epoxy resin composition of the present invention can be obtained by uniformly mixing each component at a predetermined ratio. The epoxy resin composition of the present invention can be easily made into a cured product by a method similar to a conventionally known method. For example, by mixing an epoxy resin, a curing agent, a curing accelerator, and if necessary, an inorganic filler, a pigment, a release agent, a silane coupling agent, and the like at a temperature of 70 to 110 ° C. with an extruder, a roll, a kneader, etc. An epoxy resin composition can be obtained.
[0024]
The cured product of the present invention can be obtained by molding the obtained epoxy resin composition using a casting mold, a transfer molding machine or the like, and further post-curing at 80 to 200 ° C. for 2 to 10 hours.
[0025]
Hereinafter, the present invention will be described in more detail with reference to examples. Moreover, unless otherwise indicated in an Example, a part shows a weight part.
[0026]
Reference Examples 1 to 3, Example 4, Comparative Examples 1 and 2
The formulations shown in Table 1 were mixed uniformly with a mixing roll to obtain an epoxy resin composition. This composition was pulverized and a tablet was obtained using a tablet machine. The obtained tablet was molded with a transfer molding machine to mold a 10 × 4 × 90 mm test piece. This test piece was cured at 180 ° C. for 6 hours. The test piece is held vertically to the clamp, the flame of the burner is adjusted to a 19 mm blue flame, and 9.5 mm of the flame is contacted to the center of the lower end of the test piece for 15 seconds. After the flame contact, the burner was released and the combustion duration was measured. Further, after flame extinction, the flame contacted immediately for 15 seconds, the burner was released, and the combustion duration was measured. Table 2 shows the average value of the burning duration of 10 samples.
[0027]
Further, each sample was pulverized, and about 10 mg of a 100-200 mesh particle size was collected, and the heating rate was 10 ° C./min. , Nitrogen or air flow rate 150 ml / min. Then, thermogravimetric analysis was performed using a thermogravimetric analyzer (TG / DTA220, manufactured by Seiko Denshi Kogyo Co., Ltd.). The results are shown in Table 2.
[0028]
In addition, the used epoxy resin, hardening | curing agent, and hardening accelerator are shown below.
1. Epoxy resin resin A: NC-3000PL (glycidylation product of phenol and bismethoxymethylbiphenyl condensate, epoxy equivalent of 274 g / eq., Manufactured by Nippon Kayaku Co., Ltd.)
Resin B: XP-2030 (glycidylation product of a condensation product of phenol and xylylene glycol, epoxy equivalent 238 g / eq., Manufactured by Nippon Kayaku Co., Ltd.)
Resin C: EPPN-502H (glycidylated product of phenol / salicylaldehyde condensate, epoxy equivalent of 169 g / eq., Manufactured by Nippon Kayaku Co., Ltd.)
Resin D: EOCN-1020 (glycidylated product of condensate of cresol and formaldehyde, epoxy equivalent 200 g / eq., Manufactured by Nippon Kayaku Co., Ltd.)
Resin H: BREN-105 (glycidylated brominated phenol novolak, epoxy equivalent 274 g / eq., Bromine content 35%, manufactured by Nippon Kayaku Co., Ltd.)
2. Curing agent resin E: MEH-7851 (Condensate of phenol and bismethoxymethylbiphenyl, hydroxyl group equivalent 206 g / eq., Manufactured by Meiwa Kasei Co., Ltd.)
Resin F: Xylok XLC-225-3L (condensate of phenol and xylylene glycol, hydroxyl group equivalent 170 g / eq., Manufactured by Mitsui Chemicals, Inc.)
Resin G: PN-80 (phenol novolak, hydroxyl group equivalent 105 g / eq., Manufactured by Nippon Kayaku Co., Ltd.)
3. Curing accelerator TPP: Triphenylphosphine (manufactured by Junsei Chemical Co., Ltd.)
4). Other Sb: Antimony trioxide (manufactured by Mitsuwa Chemicals Co., Ltd.)
[0029]
Table 1
Reference Example Comparative Example Resin 1 2 3 4 1 2 3
A 274 274-----
B--238 238---
C − − − − − 169 −
D − − − − 200 − 200
E 206 − − 206 − − −
F-170 170----
G----105 105 112
H − − − − − − 17.1
TPP 5.5 2.7 2.4 2.4 4.7 2.0 1.7 2.0
Sb − − − − − − 6.0
[0030]
Table 2
Combustion test Thermogravimetric analysis
Combustion duration Nitrogen Medium Air First time Second time Second inflection Second inflection Maximum peak Maximum peak (second) (second) Up to the point of the point up to the point
Weight decrease temperature Weight decrease Ascent temperature
(%) (° C) (%) (° C)
Reference Example 1 2 4 46 466 56 483
2 1 3 33 442 54 471
3 3 8 47 482 53 481
Example 4 4 8 45 438 60 455
Comparative Example 1 13 26 56 446 65 445
2 Not extinguished 58 434 60 450
3 1 10 − − − −
Note 1) For Comparative Example 3 only, flame contact time 10 seconds × 2; for others, flame contact time 15 seconds × 2
[0031]
【The invention's effect】
As can be seen from Table 2, in the epoxy resin composition of the present invention, the combustion duration time in the combustion test is significantly shorter than in Comparative Examples 1 and 2. Further, even when compared with Comparative Example 3 in which brominated epoxy resin, antimony trioxide (content 3% by weight converted as bromine, 3% by weight antimony trioxide added) was added as a flame retardant and flame retardant aid, It is a composition useful for electrical and electronic parts that have an equivalent combustion duration and are environmentally friendly and have excellent flame resistance.

Claims (5)

1) phenol and halogen in excess of epoxy resin (0.2 wt% is a glycidylated condensation product of xylylene glycol, or epoxy resin containing phosphorus are excluded)
2) The epoxy 0.3-1.5 equivalents to the epoxy groups of the resin, curing agent is a condensate of phenol and bis-methoxymethyl biphenyl (excluding the curing agent containing halogen or phosphorus)
3) A flame retardant epoxy resin used for electrical and electronic parts, containing 0.2 to 6.0 parts by weight of an accelerator as an essential component per 100 parts by weight of the epoxy resin and containing no halogen, antimony or phosphorus flame retardant. Composition . The flame retardant epoxy resin composition according to claim 1, wherein the accelerator is phosphine, imidazole, or tertiary amine. The flame retardant epoxy resin composition according to claim 2, wherein the accelerator is phosphine. The flame retardant epoxy resin composition according to claim 3, wherein the accelerator is triphenylphosphine or bis (methoxymethyl) phenylphosphine. Hardened | cured material formed by hardening | curing the epoxy resin composition as described in any one of Claims 1 thru | or 4 .