TW200930779A - Adhesive composition for halogen-free coverlay film and coverlay film using the same - Google Patents

Abstract

The invention relates to an adhesive composition for halogen-free coverlay films used for producing coverlay films for protecting flexible printed circuit boards and to a coverlay film using the same. More particularly, the invention relates to an adhesive composition for halogen-free coverlay films meeting all requirements of flame retardancy, adhesiveness, heat resistance, bleed-out, flowability, etc. and to a coverlay film using the same. To this end, the adhesive composition for halogen-free coverlay films, characterized by comprising: (1) nitrile butadiene rubber (NBR) comprising carboxyl groups and having a molecular weight between 10,000 and 200,000, and also a content of acrylonitrile of 20 to 40 parts by weight, (2) non-halogen multifunctional epoxy resin having two or more epoxy groups per molecule and a molecular weight between 200 and 1,000, (3) a hardener, (4) a curing accelerator, (5) a non-halogen phosphorus flame retardant having the content of phosphorus flame retardant more than 10% by mass and having a thermal cracking temperature higher than 300 DEG C, and (6) inorganic particles, e. g., aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, antimony trioxide, or silica, etc.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition for a halogen-free cover film for protecting a flexible printed circuit board, and a cover film using the same. More specifically, the present invention relates to an adhesive composition for a halogen-free cover film which meets all the requirements for fire resistance, adhesion, heat resistance, flow resistance, flowability, etc., and a use thereof Cover film related. BACKGROUND OF THE INVENTION Recently, the application of flexible printed circuit boards has increased significantly with the advent of light, thin and highly integrated electronic consumer products. Therefore, the use of a cover film for protecting circuits and the demand for improvement in adhesion, heat resistance, fire resistance, flowability, and the like are also increasing. 15 20 Electronic products At the same time, in Europe, it is necessary to develop environmentally friendly materials in response to regulations such as WEEE and R〇HS. However, the adhesive for electronic materials (for example, a conventional cover film or semiconductor encapsulating material is a compound containing, for example, a dentate atom used as an anti-flame agent. Therefore, the adhesive is removed. When the agent burns, it will produce, for example, a toxic gas based on Dioxin: a, currently, there is no (4) adhesive, in general, a cover film is made by using a semi-curing adhesive. The side of a heat-resistant film is coated into a layer, and it is provided with a release sheet for protecting the reducing agent. Since the riding cover is used for adhesion 5 200930779 5 ❹ 10 15 ❹ 20 On flexible printed circuit boards (PCBs) to protect these printed circuits, they need to have the necessary physical properties of heat resistance, adhesion, fire resistance and similar properties. A cover film must have all of these necessary physics. The nature, and its halogen-free characteristics are even necessary for environmental protection. The traditional adhesives used for the cover film are usually made of ring-based resin, acrylic resin, phenol resin, polyester, etc. Foundation, but all of them use fire retardants based on, for example, odorant elements, and they are environmentally friendly. For reasons of environmental protection, halogen-based fire retardants should be avoided, so no application has been developed. A cover film of a halogen fire retardant, but the like does not meet all of the above required physical properties. I: SUMMARY OF THE INVENTION The present invention is conceived to provide a non-folk cover that meets all of the necessary physical properties described above. An adhesive composition of ruthenium, and a cover film having the composition of the adhesive. One of the objects of the present invention is to provide two adhesive compositions for a ii-free cover film, and a composition having the adhesive The cover film of the article, which may conform to the physical properties necessary for the fire resistance, the adhesiveness m flow purity and the flowability, and the like, etc. The above object of the present invention is The adhesive composition of the element cover film is achieved, and the characteristics thereof include: (1) - containing a ketone group and having a molecular weight of between 1 〇, 〇〇〇 and 200 000 Nitrile rubber (NBR), and at the same time the content of acrylonitrile is 2 parts by weight (M0 parts, (7)- 6 200930779 has two or more epoxy groups per molecule and - between 2 〇〇 and 丨, 〇 a halogen-free polyfunctional epoxy resin having a molecular weight between ruthenium, (3) a hardener '(4) a curing accelerator, (5) a phosphorus content having a mass equal to or exceeding 1% and a a halogen-free phosphorus anti-fired agent equal to or higher than 3 〇 (the thermal cracking temperature of rc, and (6) inorganic such as aluminum hydroxide, magnesium hydroxide, oxidized, magnesium oxide, cerium oxide or cerium oxide The ratio of the inorganic particles to the halogen-free phosphorus fire retardant in the adhesive composition is in accordance with the following conditions: (UY is less than or equal to [_χ+3〇] (YS-Χ+30)' In this case, the X system is inclusively between 10 and 25 (6$Χ$25); and (2) if the X system is inclusively between 6 and 8 (6SXS8) 'Υ is greater than or Equivalent to Bu 2χ+22] (γ2_2χ+22); if X is intrinsically between 8 and 12 (8SXS 12), Υ is greater than or equal to [·Χ+14] (Yg-X+14); Or if the X system is inclusively Between 12 and 25 (12SXS25), Υ is greater than or equal to 2 (γ22), where "X" is 15" based on the total weight of the adhesive composition is 100 parts by weight The weight of the halogen-free phosphorus fireproofing agent, and "?" is "the weight of the inorganic particles based on the total weight of the adhesive composition based on 100 parts by weight". Preferably, the dentate-free phosphorus fire retardant is a fire retardant of an organic phosphinic acid compound and the inorganic particulate is aluminum hydroxide. The above object of the present invention is achieved by a cover film having an adhesive composition for a halogen-free cover film, characterized in that the adhesive composition for a halogen-free cover film is applied to a polymerization. On the yttrium imide substrate as an adhesive layer. Brief Description of the Drawings 7 200930779 The following features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the drawings, wherein: Figure 1 is attached to an electrolytic copper. Covering of the film - top view; side view) Figure 2 shows schematically the traceability of a relevant standard (in the case of 〇 ❹ ❹ Figure 3 shows schematically the traceability of a non-conforming standard ( In the form of X); and < Figure 4 schematically shows a sheet of a copper film 10 having a pattern formed thereon.

C. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, the present invention will be described in more detail with reference to the specific examples and the drawings of the present invention. ^ 15 ^ This artist will be able to understand the specific examples to illustrate the invention in more detail, and the scope of the invention should not be limited to that. In the halogen-free cover film, a nitrile rubber (hereinafter also referred to as R,,) containing a ketone is used, and a weight average molecular weight of 2,000 to 200,000 is straight, and 20 is 1 〇. , 〇〇〇 to 200,000, a series of 1 〇 to 6 〇 θ. / L /, is preferably heavier than ° /. The acrylonitrile content is preferably from 20 to 40% by weight, and 1 is the (f) carboxyl group content. In this case, if the weight average molecular weight is less than, the thermal stability is poor, and if the system is higher than the fine surface of 200930779, its solubility in the solvent is poor, and at the same time it is formed. The viscosity of the solution will increase, resulting in poor processability and reduced adhesion. If the content of the acrylonitrile is less than 20% by weight, the solubility in the solvent is lowered. A content of more than 40% by weight of the acrylonitrile results in poor electrical insulation performance. If the content of the carboxyl group is between 5 and 20% by weight, it is easier to adhere to NBR, other resins, and the adhesive substrate, and the adhesion is increased. ❹ ❹ At the same time, the epoxy resin used in the adhesive composition for the halogen-free cover film according to the present invention is a polyfunctional halogen-free one having 2 or more cyclic 10 oxy groups per molecule. The epoxy resin is, for example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol path type epoxy resin, a methyl type epoxy resin, # and the like. The epoxy resin may be used singly or in combination of two or more types thereof. The content of the 15 multifunctional non-automatic epoxy resin in the present invention is 50 parts by weight on the basis of the basis of the weight of the dirty, wherein the equivalent of the epoxy group (g/eq) The system is between shoulders and bribes. Less than the weight (10) part of the versatile = the content of the base resin will cause the adhesion to decrease by = drop: so the obtained composition is used as an adhesive. If the versatility does not contain 200 parts by weight of 20 parts by weight, the obtained film having a binder resin content exceeding the film cannot be maintained. Because it is too brittle to produce at the same time, only the agent, according to the hairpin, can be used as a hardening agent for the epoxy tree 0 without the hardening of the composition of the ship (4). _化_specific amine based on 200930779 based hardener, anhydride based hardener, phenol resin based hardener, etc., etc., which can be independently or in two or more Types are used in combination. The content of the aforementioned hardener in the present invention is from 1 to 20 parts by weight based on 100 parts by weight of the epoxy-based resin. 5 Meanwhile, an organic or inorganic peroxide may be used as a crosslinking agent for the rubber in the present invention in an amount of 1 to 5 parts based on 100 parts by weight of the NBR in the present invention. weight. Meanwhile, as long as it can be used to promote the reaction between the above epoxy resin and the hardener, the curing accelerator used in the adhesive composition for the halogen-free cover film according to the present invention is not Limited to a specific type. Specific examples of the curing accelerator are imidazo-based compounds, for example, 2-methylimidazolium, 2-ethyl-4-mercaptocarbazolyl, and the like; phosphine-based acceleration Agents, for example, triphenylphosphine, tetraphenyl lin, tetraphenyl succinic acid' and the like. These may be used singly or in combination of two or more of them, and the content thereof is from 0.1 to 5 parts by weight based on the weight of the epoxy group. The dentate-free flame retardant for the adhesive composition of the dentate-free cover film of the element-free atom according to the present invention is a phosphorus-based compound. Preferably, the desired property is such that the phosphorus content should be more than 20 10% of the mass; the thermal cracking temperature of the crucible is equal to or higher than. c; and it is not soluble in water or a typical organic solvent such as acetone, methyl ethyl steel, toluene, and the like. A specific example of the halogen-free flame retardant according to the present invention which meets these requirements and which can be obtained commercially is ‘Exolit 0P935 (taken from 200930779)

Clariant, which has a mass of 23 〇/〇 of phosphorus,).无机 10 The inorganic particles used in the adhesive composition for the halogen-free cover film according to the present invention are used for achieving heat resistance and fire resistance in the adhesive, and further improving impact resistance. Specific examples of useful inorganic particles are aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, antimony trioxide, antimony oxide, and the like. A preferred content of one of the inorganic particles is a weight of 2 to 6 parts by weight based on 1 part by weight of the NBR. A content of less than 20 parts by weight results in a decrease in the fire resistance, flowability, and impact resistance of the adhesive. The content of more than 6 parts by weight may result in a decrease in the physical properties such as adhesive flowability, adhesion, and the like. Meanwhile, the ratio of the elemental phosphorus fire retardant to the inorganic particles is in accordance with the following conditions: (1) the Y system is less than or equal to [-X+30] (YS-X+30), in which case the X system is Inclusively between 6 and 25 (6SXS25); and (2) 15 If the X system is inclusively between 6 and 8 (6SX$8), Y is greater than or equal to [-2X+22] ( Y2-2X+22); if the X system is inclusively between 8 and 12 (8SXS12), Y is greater than or equal to [_Χ+14](Υ2-Χ+14); or if the X system is inclusively Between 12 and 25 (12$Xg25), Y is greater than or equal to 2 (Υ^2), where "X" is "1% of the total weight of the adhesive composition." "weight of the halogen-free phosphorus fireproofing agent based on the weight", and "Y" is "the weight of the inorganic particles based on the total weight of the adhesive composition is 1 part by weight" The adhesive composition of the above components is uniformly mixed to have a viscosity of 100 to 2,000 by using, for example, methyl ethyl ketone, decyl alcohol, benzoquinone, toluene, tetrahydrofuran, benzene, and the like. CPS and preferably from 200 to 800 CPS. The adhesive composition mixture was then applied to a thin film of heat until the thickness of the coating was 25 μm. The film was cured at 5 to 170 ° C for 1 to 10 minutes. A release sheet was laminated thereon to obtain a cover film. Hereinafter, the present invention will be described in more detail by way of the specific examples and comparative examples. It should be noted that the present invention is not limited to the specific examples thereof. The materials used in these specific examples and comparative examples are listed below 10:

(1) NBR A : 27 weight ° /. Acrylonitrile '3.5% by weight of carboxyl (2) anthraquinone based resin A. YD-011 ' Epoxy equivalent: 475, available from Kukdo Chemical 15 Co. B: Epicoat 828, epoxy equivalent: i 85, Nipp〇n Ep0Xy Resin Co. C EOCN-103, Epoxy Equivalent: 209, Nippon Chemical Co. 20 (3) Hardener A: DDS (diamino 2 abbreviated) B : HF-3M, OH equivalent: 1〇7, MeihwaCo·Company (4) Curing accelerator A: 2MI (methylimidazo) 12 200930779 (5) No fire retardant A: OP-935, phosphorus content: 23% by weight, times The phosphonic acid compound, Clariant Co.'s thermal cracking temperature is equal to or higher than 3 ° C. B: SPB-100' phosphorus content: 13% by weight, phosphazene compound, 〇tsuka 5 Chemical c., company, the thermal cracking temperature is equal to or higher than 300. Hey. Inorganic Formula A: Alumina (Average Particle Diameter: 〇10 Specific Example 1 The components described in parts by weight in Table 1 (30% solids below) are uniformly homogenized by a homogenizer Mixing and dispersing in the solvent of the methyl ethyl group. The mixture is then applied to a polyimide film having a thickness of 12·5 μm to a thickness of 25 μm after the coating is dried, and The coated films were each thermally cured in a baking oven at 5 ° C for 1 minute and 15 minutes, and then at 60 ° C for about 3 minutes in the baking oven. The resulting dried The film is laminated with a release film to produce a cover film. In addition to the adhesive components of the specific examples 2 to 14 in Table 1 below, respectively, the cover film is combined with The production of hydrazine was carried out in the same manner as in Example 1. 13 200930779 Table 1: Specific components (parts by weight) NBR epoxy resin hardener curing accelerator fire retardant inorganic particles AABCABAABA Specific Example 1 30 30 10 0 5 0 0.05 7.0 0.0 18.0 Specific example 2 30 30 10 0 5 0 0.05 5.5 0.0 9.0 Specific Example 3 30 30 10 0 5 0 0.05 7.0 0.0 5.5 Specific Example 4 30 30 10 0 5 0 0.05 9.0 0.0 3.5 Specific Example 5 30 30 10 0 5 0 0.05 10.5 0.0 1.8 Specific Example 6 30 30 10 0 5 0 0.05 12.5 0.0 1.8 Specific Example 7 30 30 10 0 5 0 0.05 21.7 0.0 2.0 Specific Example 8 30 30 10 0 5 0 0.05 25.7 0.0 2.1 Specific Example 9 30 30 0 10 2 5 0.05 7.4 0.0 5.5 Specific Example 10 30 30 10 0 5 0 0.05 6.5 0.0 25.8 Specific Example 11 30 30 10 0 5 0 0.05 10.7 0.0 21.3 Specific Example 12 30 30 10 0 5 0 0.05 15.0 0.0 17.2 Specific Example 13 30 30 10 0 5 0 0.05 25.7 0.0 6.4 Specific Example 14 30 30 10 0 5 0 0.05 26.7 0.0 5.3

❹ Comparative Examples 1 to 13 The cover film was produced in the same manner as in Concrete Example 1, except that the adhesives of Comparative Examples 1 to 13 in the following Table 1 were separately mixed. 14 200930779 Table 2: Components of comparative examples (parts by weight)

〇 、 The properties of the cover film produced by the above-mentioned components and the above-described manner are evaluated in the following manner, and the results are shown in Table 3 below.

1. Sticky Lingzhi _ In each of these specific examples and comparative examples, the cover film produced by ... is etched with a processing condition of 17 (rc / 40 kgf / 40 minutes of hot pressing, and adhered On the electrolytic copper film to a thickness of 35 μm, each film is knurled to a width of 1 cm and a length of 1 〇 cm. After fixing the polyimide polyimide film 15 10 200930779 film, each copper film is at a 90 In the direction of the degree, the force is pulled at a speed of 50 mm/min to measure the force value in time and represent the average value of an adhesiveness (JIS C6481). 2. Welding property 5 by means of In the same manner of determining the adhesion, an electrolytic copper film was adhered to each of the cover films, and the films were then cut into 5 cm x 5 cm. The film was immersed in a soldering pot at a predetermined temperature for 1 , second, and then taken out. The change in appearance, such as delamination or color change, is examined to test the maximum temperature at which no change will occur. 10 3. Prevention against such cover films produced by these specific examples and comparative examples The sample is at 170° by one side of each film. C/40 kgf / 40 minutes, hot pressing to the adhesive of the cover film produced in the specific example 1, to evaluate the fire resistance according to the provisions of UL94 V-0. When the knot 15 is in line with the relevant When the standard is marked, “〇,,, and when the result does not meet the standard, the “X” is marked.

Five circular holes having a diameter of 5 mm were dug at intervals of 2 cm on each of the covering films produced according to the specific examples and comparative examples. The film was then adhered to a 35 μm thick electrolytic copper film by a hot pressing at 170 ° C / 40 kgf / 40 minutes. Adhesives that flow around the holes are examined with a microscope. When the shape of the viscous agent is uniform and the color is not changed, it is marked as °, when the shape is inconsistent or it has a significant amount of adhesive fused 16 200930779 Refer to Figures 1, 2 and 3 for the symbol "X". 5 · Flowability First, a flexible copper film laminate was formed into a pattern having a circuit having a width of 1 mm as shown in Fig. 4. Each of the cover films produced according to the specific examples and the specific examples of -5 was adhered to the circuits by heat pressing at a temperature of 170 ° C / 40 kgf / 40 minutes. The gap between the circuit patterns is examined with a microscope to check if the adhesive in the cover film fills the gap. When 100% of the gap is filled with adhesive, Ο is marked “〇”, and when some parts are not completely filled, 10 “X” is marked. ❹ 17 200930779 Table 3: Results of each specific example Fire resistance (V-0) Adhesion (N/cm) Solder heat resistance CC) Flowability and flowability Specific example 1 〇12 330 〇〇 Specific example 2 〇14 330 〇〇 Specific Example 3 〇 13 330 〇〇 Specific Example 4 〇 12 330 〇〇 Specific Example 5 〇 11 330 〇〇 Specific Example 6 〇 10 320 〇〇 Specific Example 7 〇 6 300 〇〇 Specific Example 8 〇 6 290 〇〇 Specific Example 9 〇12 340 〇〇Specific Example 10 〇8 320 〇〇Specific Example 11 〇7 320 〇〇Specific Example 12 〇7 310 〇〇Specific Example 13 〇6 300 〇〇Specific Example 14 〇6 300 〇〇

18 200930779 Table 4: : Results of each specific example

Actually, it can be used in the future + 94V-0, and the properties of the cover film must be unconditionally conformed to UL © ❹ 5 The elemental atom H should be greater than 6 _ ', which is lower than the general package and cover film. The nature of the flow--conforms to the relevant leveling of the prisoner's horse. The unevenness of the agent will be in the subsequent plating process. At the same time, the nature of the flowability - it must be 100% filled (according to the standard because of the incomplete filling phenomenon between the circuit patterns of the cover film, the pattern line is interrupted, separated by bubbles , etc. However, referring to the results of the comparative examples produced (which are shown in Table 4), since these Comparative Examples 1 and U do not include a halogen-free phosphorus fire retardant, and 19 10 200930779 does not pay for fire resistance. The standards of Comparative Examples 2, 3, 4, 5, and 6, etc., all use fireproofing agents and inorganic particles, but the content of such materials is too small, so the obtained film does not meet the fire resistance standard. Conversely, For Comparative Examples 7, 8, 9, and 10, and the amount of the fire retardant and the inorganic particles were too large, the fire resistance of the .5 fire resistance was in conformity with the standard, and the flowability was not met. Meanwhile, in Comparative Example 12 and. A halogen-free dish fire retardant is used in 13 but the resulting film has a lower thermal cracking temperature (less than 3 〇〇.〇, so it conforms to other physical properties, but its trajectory The nature of the product does not meet the standard. Table 3 showing the results of the specific examples of the present invention, all the results of 10 are floating UL94 vo, and the resulting film is also more than 6 N/cm. The nature of the flow is also in accordance with the standard. For the nature of flowability, it is possible to obtain a 1%-filled effect without pattern breakage and bubble separation which would result in an incomplete filling phenomenon between circuit patterns, and the like. It can be found that the film produced in the comparative example 15 does not meet all of the above requirements. © The cover film produced in accordance with the present invention will conform to the fire resistance, adhesion, heat resistance, flow trace required for a cover film. Sexuality, Mobility, etc. Based on the foregoing description, various modifications and changes can be made without departing from the actual spirit and scope of the invention. It should be understood that the foregoing description is for illustrative purposes. It is not intended to limit the scope of the invention, which is defined by the scope of the appended claims. The present invention is based on each and every novel feature, and each and every The use of "contains " the use of this verb does not preclude the existence of elements other than those described in the 20 200930779 proposal. Use the article "a" or "one" before a component. It is not excluded that there are a plurality of such elements. c. Brief description of the drawing 1 Fig. 1 is a side view of one side of a cover film adhered to an electrolytic copper film; Fig. 2 is a schematic view showing compliance with a correlation Standard traceability (represented by 〇); Figure 3 schematically shows the traceability (represented by X) that does not meet a relevant standard; and 10 Figure 4 shows schematically a flexible copper film formed with a pattern Plate. [Main component symbol description] 1.. Cover film 2.. Electrolytic film 3··. Adhesive flowing out on the cover film 4. Copper with a width of 1 mm Figure 21

Claims (1)

200930779 X. Patent application scope: l An adhesive composition for a non-functional coating film, characterized in that it comprises: _ (1) a nitrile rubber (NBR) containing a carboxyl group and having a medium a molecular weight of between 10 and 200,000, and a content of 20-40 parts by weight of acrylonitrile; (2) a dentate-free polyfunctional epoxy resin having two or two in each molecular enthalpy More epoxy groups and having a molecular weight between 200 and 1,000; 10 (3) - hardener; (4) a curing accelerator; (5) - halogen-free phosphorus fire retardant having a content equal to or More than 1% by mass of phosphorus, and having a temperature equal to or higher than 30 (the thermal cracking temperature of rc; and 15 (6) inorganic particles, such as aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium strontium oxide, three 2. The cerium oxide or cerium oxide, etc. 2. The adhesive composition according to claim 1, wherein the ratio of the halogen-free phosphorus fire-retardant to the inorganic particles meets the following conditions: 20 (1) The lanthanum is less than or Equal to [-X+30] (YS-X+30), in this case the X system contains The ground is between 6 and 25 (6SXS25); and (2) if the X system is intrinsically between 6 and 8 (6SXS8), Y is greater than or equal to [-2X+22] (Y2-2X+ 22); if the X system is inclusively between 8 and 12 (8SXS12), Y is greater than or equal to [-X+14] 22 200930779 (Yg-X+14); or if the X system contains inclusive Between 12 and 25 (12SXS25), Y is greater than or equal to 2 (Y22), wherein "X" is "the halogen-free weight based on 100 parts by weight of the total weight of the adhesive composition" "When the weight of the fire retardant is filled", and 5 "Υ" is "the weight of the inorganic particles based on the total weight of the adhesive composition of 100 parts by weight". The adhesive composition of the present invention is characterized in that the halogen-free phosphorus fire retardant is an organic hypophosphorus compound fire retardant, and the inorganic particles are aluminum hydroxide. 10 4. The type has a halogen-free cover film A cover film for an adhesive composition, characterized in that the adhesive composition for a non-foam cover film according to any one of claims 1 to 3 is applied It is used on a polyimide substrate to serve as an adhesive layer. twenty three