CN101781442B - Halogen-free resin glue and the film produced therefrom - Google Patents

Abstract

A halogen-free resin adhesive, characterized in that it comprises: component (A): epoxy resin; component (B): composite hardener, wherein the composite hardener is prepared by mixing benzoxazine (BZ) resin and aminotriazine phenol formaldehyde (ATN) resin in a predetermined ratio; component (C): aromatic condensed phosphate ester; and component (D): filler, wherein the filler comprises aluminum hydroxide and silicon dioxide; therefore, a film made by impregnating the halogen-free resin adhesive can have good heat resistance, flame retardancy and low hygroscopicity.

Description

Halogen-free resin glue and the film produced therefrom

technical field

The invention relates to a halogen-free resin glue solution, especially a halogen-free resin glue solution with composite hardener, aromatic condensed phosphoric acid ester and filler.

Background technique

At present, the application range and fields of printed circuit boards are quite extensive. Generally, electronic components in electronic products are inserted on printed circuit boards. Today's printed circuit boards are used in order to meet the application range of high-power and high-heat components. The heat dissipation effect of printed circuit boards is developed and researched to improve the heat dissipation efficiency and high power of circuit boards.

The printed circuit board is made of impregnated film (PP), or multiple films such as copper clad laminate (CCL) or copper foil, which are fully pressed by thermal pressing; and the impregnated film is made of glass fiber The cloth is impregnated with an epoxy resin prepreg to form a glue solution, and then undergoes subsequent processes such as drying to form a thin film.

However, due to the rise of environmental protection awareness in recent years, many consumer electronics have gradually stopped using halogen-containing copper foil substrates and switched to halogen-free copper foil substrates. The epoxy resin used to make the above-mentioned substrates can be divided into two types of hardeners: Dicyandiamide and Phenol novolac resin, but the former substrate has high moisture absorption and heat resistance. Disadvantages, the latter's low moisture absorption and heat resistance are better than the base material of the dicyandiamide hardening system, but further research and development is required to match the glue composition with a variety of phenolic resin hardeners. For example, Taiwan Patent No. 293831 discloses that a glue solution composed of a benzoxazine resin (BZ resin) and a phosphorous compound is used to achieve a flame-resistant property of the prepared resin film. Another example is Taiwan Patent No. 583258, which discloses a hardener that utilizes benzoxazine resin (BZ resin) and phenols, compounds with triazine rings and aldehydes in combination with a copolymer resin (ATN resin), The glue of this composition can improve the flame resistance of the film, but it is recommended to use a large amount of BZ type resin hardener, while the relative amount of ATN resin is relatively small, so although it can increase the Tg of the film and reduce the water absorption of the film , but the tin-blowing result (heat resistance) of the film will be reduced, and the substrate made has the problems of poor toughness and excessive addition will lead to poor heat resistance.

In order to overcome the above-mentioned defects, the present inventor proposes an invention with reasonable design and effectively improving the above-mentioned defects.

Contents of the invention

The main purpose of the present invention is to provide a halogen-free resin glue, which has a composite hardener, so that the film made can have heat resistance, flame resistance and low hygroscopicity.

Another object of the present invention is to provide a halogen-free resin glue solution, wherein fillers and phosphorus-containing compounds are added to improve the film made by impregnating glass fiber cloth in the halogen-free resin glue solution. Excellent heat resistance, flame resistance and low moisture absorption.

The present invention provides a halogen-free resin glue, which is characterized in that it comprises: component (A): epoxy resin; component (B): composite hardener, wherein the composite hardener is made of benzoxazine (Benzoxazine) (BZ) resin and amino triazine phenolic (Amino triazinenovolac) (ATN) resin are mixed in a predetermined ratio; component (C): aromatic condensed phosphate; and component (D): filler, Wherein the filler includes aluminum hydroxide and silicon dioxide.

The present invention also provides a film with high heat resistance, high flame resistance and low water absorption, which is formed by immersing the glass fiber cloth in the above-mentioned halogen-free resin glue solution, curing and drying.

The present invention has the following beneficial effects: the present invention uses two kinds of hardeners to form a composite hardener, and uses the composite hardener in a main resin to form a halogen-free resin glue. Therefore, when the glass fiber cloth Immersing in the glue solution can improve the flame resistance of the impregnated film, and can also take into account the water absorption of the film; at the same time, adding low molecular weight phosphorus-containing compounds to the glue solution can increase the flame resistance of the above-mentioned film.

In order to further understand the characteristics and technical content of the present invention, please refer to the following detailed description of the present invention.

Detailed ways

The present invention provides a composite curing agent, which is added to epoxy resin, so that the glass fiber cloth can be formed into a material with high heat resistance and low hygroscopicity (water absorption) after the dipping step. The film, and the above-mentioned film and copper foil can be used to produce a laminate with heat resistance and moisture absorption characteristics in a hot pressing manner. In addition, the present invention further adds a low-molecular-weight phosphorus-containing compound to improve the heat-resistant and flame-retardant properties of the prepared resin; moreover, the present invention adds an appropriate proportion of fillers to produce a resin with better flame-resistant and flame-resistant properties. Film with thermal properties.

The composite hardener is mainly formed by mixing the composite hardener with benzoxazine (BZ) resin and aminotriazine novolac (ATN) resin in a predetermined ratio. Aminotriazine phenolic (ATN) resin is a copolymer resin of phenols, compounds with triazine rings and aldehydes. When the above-mentioned phenols and compounds with triazine rings and aldehydes produce copolymers, the phenols used can be For example: polyphenols such as phenol or bisphenol A, bisphenol F, bisphenol S, or alkylphenols such as cresol, xylenol, ethylphenol, butylphenol, aminophenol, phenyl Phenol and the like may be used alone or in combination of two or more. Generally speaking, when phenol and bisphenol A, or phenol and alkylphenol are used together, the reactivity is suppressed and the moldability is better than when phenol is used alone; at the same time, it is more flame retardant than when bisphenol A or alkylphenol is used alone Sex is good. In addition, the compound having a triazine ring includes, for example, guanamine derivatives such as melamine, benzoguanamine, and acetylguanamine, and cyanuric acid derivatives such as cyanuric acid, methyl cyanurate, and ethyl cyanurate. , or isocyanuric acid derivatives such as isocyanuric acid, methyl isocyanurate, ethyl isocyanurate, etc. Among them, melamine has good heat resistance and flame retardancy, and is ideal in terms of cost. However, the present invention is not limited to the above, and the type and amount of the compound having a triazine ring can be selected according to the purpose, and the optimum flame retardancy, reactivity and heat resistance can be obtained by adjusting the nitrogen content. Furthermore, the aldehydes used above may be, for example, formaldehyde, paraformaldehyde, trioxane, tetrahydroxymethane, etc., but are not limited to the above range. In terms of ease of use, formaldehyde is more suitable, especially formalin and paraformaldehyde.

Benzoxazine (BZ) resin is a resin with benzoxazine compounds as the main component, as long as it has benzoxazine and is hardened by the ring-opening reaction of benzoxazine, there is no other restrictions. The characteristics of benzoxazine (BZ) resin are low dielectric loss factor, high elastic modulus, high heat resistance, low water absorption, high glass transition temperature, high flame retardancy and punching processability, etc. Properly control the softening point of the BZ resin to reduce the shortcomings of its main structure being rigid and lack of toughness; at the same time reduce the interlayer peeling when the shape is punched, and improve the adhesion of the resin layer in contact with the inner circuit of the multilayer wiring board. Relay to improve the effect of inner layer shedding strength.

Therefore, in the present invention, the above two hardening resins are combined into a composite resin hardener, and the composition of the BZ and ATN resin hardeners is further adjusted to obtain the best resin glue combination formula, so as to improve the fire resistance in addition to the flame resistance. Thermal and low moisture absorption characteristics. In the following, multiple sets of combinations of BZ and ATN resins will be carried out to illustrate the best film properties achieved through the deployment of the proportions of the two resins.

Table 1

Table 1 shows three kinds of glue solutions with different composition ratios, wherein the main resin (i.e. the epoxy resin of component A) is 100 parts by weight, and the epoxy resin is o-cresol novolac epoxy resin (cresolnovalac epoxy resin), phenol Novolac epoxy resin (phenol novalac epoxy resin), bisphenol A novalac epoxy resin (bisphenol-A novalac epoxy resin), or a mixture of two or more of the above resins, but not limited to the above, and the implementation of Table 1 Example 1, Comparative Example 1 and Comparative Example 2 are mainly to change the composition of the BZ resin hardener and ATN resin hardener in the composite hardener of component B, and perform various tests on the films made of glue solutions with different compositions. Characteristic analysis. Among them, water absorption can also be called hygroscopicity, which is mainly to determine the water absorption characteristics of the film, because the film will expand and deform or absorb water vapor under the influence of the temperature and humidity of the environment. However, when the water content and humidity of the film are too high, it is easy to cause the printed circuit board to be pressed to explode or other circuit board defects, etc., so the water absorption characteristic is one of the important characteristics of the film. . Traditionally, IR spectroscopy or thermogravimetric loss analysis of the material can be performed to confirm the water absorption of the film. Therefore, it can be found from Table 1 that from the water absorption analysis of Comparative Example 1, Comparative Example 2 to Example 1, when the ratio of ATN resin hardener to BZ resin hardener is from 56/0 (without adding BZ hardener) to 48/ In the case of 8 (ie 6/1), the water absorption of the film will gradually decrease from 0.174% to 0.151%.

Heat resistance: It is the result of tin bleaching. The heat resistance test is based on the industry standard IPC-TM-650Method 2.4.13.1. The time (minutes) required to soak the heat dissipation film in a tin furnace at 288°C until it explodes. It can be known from this The film produced after impregnating the glass fiber cloth with the resin glue proposed by the invention has high heat resistance, so the time required for the plate bursting is relatively long and meets the test specifications. It can be found from Table 1 that the tin bleaching results from Comparative Example 1, Comparative Example 2 to Example 1, when the ratio of ATN resin hardener to BZ resin hardener is from 56/0 (no BZ hardener added) to 48/8 (ie 6/1), the tin bleaching result of the film will gradually increase from less than ten minutes to ten minutes (the tin bleaching time of ten minutes can usually be regarded as the best judgment standard for heat resistance).

Flame resistance: that is, flame retardancy, which is determined according to the UL 94 method. It refers to the flame resistance test of plastic materials. It is determined by the spontaneous combustion time, spontaneous combustion speed, and falling particle state of plastic material standard test pieces after flame combustion. flammability rating. According to the pros and cons of flame resistance, the order is HB, V-2, V-1, V-0, and the highest is 5V. The UL 94 test method refers to the burning of plastic materials in a vertical manner on a flame. Taking every ten seconds as a test cycle, the steps are as follows: Step 1: Put the test piece into the flame for ten seconds and then remove it, and measure the continuous burning time of the test piece after removal (T1); Step 2: The flame of the test piece After it is extinguished, put it into the flame for ten seconds and then remove it, and then measure the continuous burning time (T2) of the test piece after removal; Step 3: Repeat the experiment several times and take the average value; Step 4: Calculate the T1+T2 total. The requirement of UL 94V-0 grade is that the average single burning time T1 and T2 of the test piece shall not exceed 10 seconds, and the sum of T1 and T2 shall not exceed 50 seconds to meet the requirements of UL 94V-0. Therefore, the films made in Comparative Example 1, Comparative Example 2 and Example 1 in Table 1 can all meet the requirements of UL 94V-0.

Therefore, by analyzing the characteristics of water absorption, heat resistance and flame resistance in Table 1, when the ratio of ATN resin hardener to BZ resin hardener is 6/1, the above characteristics can be achieved quite good, In other words, the ratio of ATN resin hardener to BZ resin hardener is 6/1, which can be regarded as the best implementation mode of the present invention.

Table 2

Table 2 shows the composition of ATN resin hardener and BZ resin hardener with different ratios. According to the results of Table 2 and Table 1, the best ratio of ATN resin hardener to BZ resin hardener is 48/8 (6/1 ), but the composition range of ATN resin hardener and BZ resin hardener can be relaxed from 1/1 (such as the ratio of control 7 is close to 1/1) to 8/1 (such as the ratio of control 9 is close to 8/1). Table 2 further shows the difference in heat resistance and the number of moles of epoxy groups and hydroxyl groups in different proportions. The epoxy group mentioned above is the epoxy resin in the main dose, while the hydroxyl group represents the ATN resin. It can be seen from Table 2 that when there are more hydroxyl groups, the heat resistance will decrease, so the proportion of hydroxyl groups (that is, ATN resin) must also be limited. From the analytical data of the control 9 of Table 2, in the control 9, the ratio of the main resin (epoxy group) to the ATN resin (hydroxyl group) is 100/50 (i.e. 2/1), and the produced film properties As shown in Table 2, it can be found that in the tin-flooding experiment of the film of Control 9, the tin-floating result of the film is only six to seven minutes, so the heat resistance does not meet the specifications. Therefore, based on the above-mentioned experimental data , the weight ratio of the epoxy resin to the aminotriazine novolac (ATN) resin is less than or equal to (≤)2.

On the other hand, the present invention further adds component (C): a phosphorus compound to the halogen-free resin glue. In order to enhance the flame resistance of the product without affecting the flame resistance and heat resistance of the resin, the present invention uses a low molecular weight flame retardant compound to increase the flame resistance of the resin of the present invention. In this specific example, an aromatic condensed phosphoric acid ester with a molecular weight of less than 600 is used in an amount of 25 to 40 parts of the main resin, and preferably 33 parts, based on [OC ₆ H ₃ (CH ₃ ) ₂ ]2P (O)OC ₆ H ₄ OP(O)[OC ₆ H ₃ (CH ₃ ) ₂ ] ₂ is the main component structure.

In addition, the present invention further adds component (D): filler in the halogen-free resin glue solution to improve the resin film with flame resistance, heat resistance and low water absorption; and in this specific embodiment, the filler includes Aluminum hydroxide and silicon dioxide, aluminum hydroxide mainly provides flame-resistant (flame retardant) properties, because aluminum hydroxide will release crystal water molecules when heated; while silicon dioxide is a material with good heat resistance. Please refer to Table 3, which shows the effects of different proportions of aluminum hydroxide and silicon dioxide on the properties of the resin film, and the main epoxy resin, ATN hardener, BZ hardener and The compositions of the phosphorus-containing compounds are all the same.

table 3

In Comparative Example 3 in Table 3, there is no filler added at all, and it can be found that the flame resistance level of the resin film has dropped to V-1 level, so the flame resistance of the film of Comparative Example 3 is not up to standard. Comparative Example 1 only adds 40 parts of aluminum hydroxide without adding silicon dioxide, so the flame resistance rating of the film of Comparative Example 1 is V-0 grade, on the contrary, the heat resistance of the film of Comparative Example 1 is not good, and its tin bleaching The result is only four to five minutes. And Comparative Example 2 only added 40 parts of silicon dioxide without adding aluminum hydroxide, so the heat resistance of the film of Comparative Example 2 rose to ten minutes from the tin bleaching result of the film of Comparative Example 1 for four to five minutes, otherwise, the comparison The flame resistance level of the film of Example 2 is reduced from the V-0 level of Comparative Example 1 to V-1 level; . Therefore, from Comparative Examples 1 to 3, it can be found that no matter whether the resin film is made without adding any filler or only adding a certain kind of filler, some characteristics will be insufficient, resulting in the specifications of the film not meeting the product requirements. Please refer to Comparative Example 5 again, in which 40 parts of silicon dioxide and 40 parts of aluminum hydroxide are added at the same time, and the characteristics of the film produced in Comparative Example 5 can meet the requirements of the product, wherein the tin bleaching result of the film exceeds ten minutes, and the film The flame resistance grade is V-0 grade. And the present invention further fine-tunes the ratio of silicon dioxide and aluminum hydroxide, wherein the number of parts of silicon dioxide is 50 parts, aluminum hydroxide then drops to 30 parts, and the making of film is carried out with this composition, wherein by table 3 It can be found that the heat resistance and flame resistance are maintained at the highest level, and the water absorption of the film is further improved, and the water absorption of the film is reduced from 0.169% in Comparative Example 5 to 0.151%, so in the best embodiment, the silica The ratio with aluminum hydroxide is 5/3, and the filler of the component (D) is 70 to 90 parts of the main resin, preferably 80 parts.

In summary, the present invention further proposes a halogen-free resin glue, which includes component (A): epoxy resin; component (B): composite hardener, wherein the composite hardener is made of benzene oxazine (BZ) resin and aminotriazine phenolic (ATN) resin are mixed in a predetermined ratio; component (C): aromatic condensed phosphate; and component (D): filler, wherein the filler Including aluminum hydroxide and silicon dioxide. And Table 4 shows the optimal composition ratio of the halogen-free resin glue solution, wherein, the halogen-free resin glue solution further includes component (E): additives, such as accelerators and solvents in Table 4, and in this In the best embodiment, the accelerator is an imidazole compound, such as 2-methylimidazole, whose function is to accelerate and control the hardening time of the glue; and the solvent is 15-30 parts of MEK, PM, cyclohexanone, etc.

Table 4

The present invention further provides a method for manufacturing a film using the above-mentioned halogen-free resin glue solution and the manufactured film. The method uses the above-mentioned halogen-free resin glue solution, which includes component (A): epoxy resin; component (B): composite hardener, wherein the composite hardener is composed of benzoxazine (BZ) resin and Aminotriazine phenolic (ATN) resin is mixed in a predetermined ratio; component (C): aromatic condensed phosphate; and component (D): filler, wherein the filler includes aluminum hydroxide and silicon dioxide , and dipping a glass fiber cloth in the glue solution. And the glue can further contain component (E): additives, such as accelerators, solvents and other compounds, but not limited to the above; in addition, the composition ratio of the halogen-free resin glue used to impregnate the glass fiber cloth It is obtained from the above-mentioned experimental data, and will not be repeated here.

In summary, the present invention has the following advantages:

1. The present invention mainly uses two kinds of hardeners to form a composite hardener, and uses the composite hardener in a main resin to form a halogen-free resin glue, so as to improve the film quality of the glue. Flame resistance, while also taking into account the low water absorption and heat resistance of the film; at the same time, low molecular weight phosphorus-containing compounds are added to the glue to increase the flame resistance of the above film.

2. On the other hand, the halogen-free resin glue of the present invention is further added with a certain proportion of fillers (aluminum hydroxide and silicon dioxide) to achieve the resin film characteristics of flame resistance, heat resistance, and low water absorption.

However, the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of patent protection of the present invention. Therefore, all equivalent changes made by using the description and drawings of the present invention are all included in the rights of the present invention in the same way. Within the scope of protection requested, I agree to Chen Ming.

Claims (9)

1. A halogen-free resin glue solution, characterized in that, comprising: Component (A): epoxy resin; Component (B): Composite curing agent, wherein the composite curing agent is formed by mixing benzoxazine (BZ) resin and aminotriazine novolac (ATN) resin in a predetermined ratio, and the composite curing agent The weight ratio of the aminotriazine novolac (ATN) resin and the benzoxazine (BZ) resin is 6, and the epoxy resin of the component (A) and the aminotriazine novolac (ATN) in the component (B) ) resin weight ratio is less than or equal to 2; component (C): aromatic condensed phosphoric acid ester, wherein the aromatic condensed phosphoric acid ester is [OC ₆ H ₃ (CH ₃ ) ₂ ] ₂ P(O)OC ₆ H ₄ OP ₍ O)[ _OC6H3 ( _CH3 ) ₂ ] ₂ ; and Component (D): filler, wherein the filler includes aluminum hydroxide and silicon dioxide. 2. The halogen-free resin glue solution according to claim 1, characterized in that: relative to 100 parts by weight of component (A), the amount of the aromatic condensed phosphoric acid ester is 25 to 40 parts. 3. The halogen-free resin glue solution according to claim 2, characterized in that: relative to 100 parts by weight of component (A), the amount of the aromatic condensed phosphoric acid ester is 33 parts. 4. The halogen-free resin glue solution according to claim 2, characterized in that: relative to 100 parts by weight of component (A), the filler in component (D) is 70 to 90 parts. 5. The halogen-free resin glue solution according to claim 4, characterized in that: the weight ratio of silicon dioxide and aluminum hydroxide in the component (D) is 5:3. 6 . The halogen-free resin glue solution according to claim 5 , further comprising: component (E): an additive, and the additive is an accelerator and a solvent. 7. The halogen-free resin glue solution according to claim 6, characterized in that: the accelerator is an imidazole compound. 8. The halogen-free resin glue solution according to claim 1, characterized in that: the epoxy resin is o-cresol novolac epoxy resin, phenol novolac epoxy resin, bisphenol A novolac epoxy resin, or both more than one mixed resin. 9. A film made by immersing glass tape in the halogen-free resin glue solution according to any one of claims 1-8.