A phenolic resin glue solution for copper-clad plate and application thereof

Abstract

The application provides a phenolic resin glue liquid for copper-clad plates, which is prepared from the following components in parts by weight: melamine modified phenolic resin 32-35 parts, tung oil modified phenolic resin 20-24 parts, curing agent 7-10 parts, accelerator 0.2-0.5 parts, additive 4-5 parts, filler 18-22 parts, toughening agent 8-12 parts and solvent 70-76 parts. The application also provides the application of the phenolic resin glue liquid for copper-clad plates. The phenolic resin glue liquid for copper-clad plates has good flame retardance and toughness.

Description

Technical Field

[0001] This invention relates to a resin adhesive, and more particularly to a phenolic resin adhesive for copper clad laminates and its application. Background Technology

[0002] Copper-clad laminate, also known as copper clad laminate, is a product made by impregnating electronic-grade fiberglass cloth with resin, then covering it with copper foil on one or both sides, and finally hot-pressing it. It is a fundamental material in the electronics industry, primarily used in the manufacture of printed circuit boards, and widely applied in electronic products such as televisions, radios, computers, and mobile communications. Phenolic resin, being inexpensive and possessing good performance, has wide applications in the automotive, electronics, transportation, and aerospace industries, and can also be used as the resin for copper-clad laminates.

[0003] Currently, the phenolic resin commonly used in copper clad laminates is linear phenolic resin. Linear phenolic resin has good heat resistance, water resistance, corrosion resistance, and mechanical properties. However, copper clad laminates have high requirements for flame retardancy. Ordinary phenolic resins generally have low flame retardancy and cannot meet the flame retardancy requirements of copper clad laminates. In addition, phenolic resins are relatively brittle and have poor toughness, which limits their further application in copper clad laminates. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a phenolic resin adhesive for copper clad laminates, which has good flame retardancy and toughness.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] A phenolic resin adhesive for copper clad laminates is made from the following components in parts by weight: 32-35 parts of melamine-modified phenolic resin, 20-24 parts of tung oil-modified phenolic resin, 7-10 parts of curing agent, 0.2-0.5 parts of accelerator, 4-5 parts of additives, 18-22 parts of filler, 8-12 parts of toughening agent, and 70-76 parts of solvent.

[0007] Furthermore, the curing agent described in this invention is triethanolamine.

[0008] Furthermore, the accelerator described in this invention is 2-methylimidazole.

[0009] Furthermore, the auxiliary agent described in this invention is 3-chloro-4-difluoromethoxyphenyl isocyanate.

[0010] Furthermore, the filler described in this invention is alumina with an average particle size of 2.6 μm.

[0011] Furthermore, the toughening agent of the present invention is prepared by the following steps:

[0012] Zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid are mixed and stirred for 40-60 minutes to obtain a mixture. The mixture is placed in an oven, heated to 110°C, and kept at that temperature for 48 hours. After cooling to room temperature, the reactant is obtained. The reactant is filtered to obtain a filter residue. The filter residue is washed three times with N,N-dimethylacetamide and then dried for 10-12 hours to obtain the auxiliary agent.

[0013] Furthermore, in the preparation steps of the toughening agent of the present invention, the ratio of zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid is 1 mmol:0.5 mmol:120 mL:0.6 g, the stirring speed is 200 rpm, the heating rate of the oven is 10 °C / hour, and the drying temperature is 75 °C.

[0014] Furthermore, the solvent described in this invention is ethylene glycol monomethyl ether.

[0015] Another technical problem to be solved by the present invention is to provide the application of the above-mentioned phenolic resin adhesive for copper clad laminates in copper clad laminates.

[0016] To solve the above technical problems, the technical solution is as follows:

[0017] The application of a phenolic resin adhesive for copper-clad laminates includes the following steps:

[0018] S1. Weigh each component of the phenolic resin adhesive for copper-clad laminates according to the weight parts, mix the melamine-modified phenolic resin, tung oil-modified phenolic resin, curing agent, accelerator, and solvent, and stir at a stirring speed of 500-600 rpm for 1-2 hours. Then add the other components and stir at a stirring speed of 800-1000 rpm for 2-3 hours to obtain the phenolic resin adhesive for copper-clad laminates.

[0019] S2. Immerse the bleached wood pulp paper in the phenolic resin solution for copper-clad laminates obtained in step S1, and bake at 150-170℃ for 1 minute to obtain a semi-cured sheet.

[0020] S3. Stack the 6 semi-cured sheets obtained in step S2 together to obtain a laminate. Cover the upper and lower surfaces of the laminate with a copper foil and place it in a hot press at 150-160℃ and 30-40MPa pressure for 80-120 minutes to obtain a copper-clad laminate.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The tung oil-modified phenolic resin used in this invention has stronger toughness than ordinary phenolic resin. However, it can only play a toughening role. With the addition of tung oil, the flame retardant performance of the resin adhesive system deteriorates. Therefore, this invention also uses melamine-modified phenolic resin with stronger flame retardancy. It is compounded with tung oil-modified phenolic resin to prepare a phenolic resin adhesive for copper-clad laminate with good toughness and flame retardancy.

[0023] 2) The toughening agent used in this invention is made by a solvothermal method from zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, etc. It has a three-dimensional network structure, which can further improve the toughness of the phenolic resin adhesive for copper clad laminates and the copper clad laminate itself.

[0024] 3) The additive used in this invention is 3-chloro-4-difluoromethoxyphenyl isocyanate, which can promote the cross-linking reaction of the resin adhesive system, effectively improve the adhesion of the phenolic resin adhesive for copper clad laminate and the peel strength of the copper clad laminate, and further improve the flame retardancy of the phenolic resin adhesive for copper clad laminate and the copper clad laminate. Detailed Implementation

[0025] The present invention will now be described in detail with reference to specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0026] Example 1

[0027] The phenolic resin adhesive for copper clad laminates is made from the following components in parts by weight: 34 parts melamine-modified phenolic resin, 23 parts tung oil-modified phenolic resin, 9 parts triethanolamine, 0.4 parts 2-methylimidazole, 4.8 parts 3-chloro-4-difluoromethoxyphenyl isocyanate, 21 parts alumina with an average particle size of 2.6 μm, 10 parts toughening agent, and 75 parts ethylene glycol monomethyl ether.

[0028] The toughening agent is made by the following steps:

[0029] Zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid were mixed in a ratio of 1 mmol:0.5 mmol:120 mL:0.6 g and stirred at 200 rpm for 50 minutes to obtain a mixture. The mixture was placed in an oven and heated to 110 °C at a rate of 10 °C / hour, and then kept at that temperature for 48 hours. After cooling to room temperature, the reactant was obtained. The reactant was filtered to obtain a filter residue, which was washed three times with N,N-dimethylacetamide and then dried at 75 °C for 11 hours to obtain the auxiliary agent.

[0030] The application of this phenolic resin adhesive in the manufacture of copper-clad laminates includes the following steps:

[0031] S1. Weigh each component of the phenolic resin solution for copper-clad laminates according to the weight parts, mix melamine-modified phenolic resin, tung oil-modified phenolic resin, triethanolamine, 2-methylimidazole, and ethylene glycol monomethyl ether, stir at 500 rpm for 2 hours, then add the other components, stir at 900 rpm for 2.5 hours to obtain the phenolic resin solution for copper-clad laminates;

[0032] S2. Immerse bleached wood pulp paper in the copper-clad laminate phenolic resin solution obtained in step S1, and bake at 160°C for 1 minute to obtain a semi-cured sheet.

[0033] S3. Stack the 6 semi-cured sheets obtained in step S2 together to obtain a laminate. Cover the upper and lower surfaces of the laminate with a copper foil and place it in a hot press at 155°C and 35MPa for 100 minutes to obtain a copper-clad laminate.

[0034] Example 2

[0035] The phenolic resin adhesive for copper clad laminates is made from the following components in parts by weight: 32 parts melamine-modified phenolic resin, 20 parts tung oil-modified phenolic resin, 7 parts triethanolamine, 0.2 parts 2-methylimidazole, 4 parts 3-chloro-4-difluoromethoxyphenyl isocyanate, 18 parts alumina with an average particle size of 2.6 μm, 8 parts toughening agent, and 70 parts ethylene glycol monomethyl ether.

[0036] The toughening agent is made by the following steps:

[0037] Zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid were mixed in a ratio of 1 mmol:0.5 mmol:120 mL:0.6 g and stirred at 200 rpm for 40 minutes to obtain a mixture. The mixture was placed in an oven and heated to 110 °C at a rate of 10 °C / hour, and then kept at that temperature for 48 hours. After cooling to room temperature, the reactant was obtained. The reactant was filtered to obtain a filter residue, which was washed three times with N,N-dimethylacetamide and then dried at 75 °C for 10 hours to obtain the auxiliary agent.

[0038] The application of this phenolic resin adhesive in the manufacture of copper-clad laminates includes the following steps:

[0039] S1. Weigh each component of the phenolic resin solution for copper-clad laminate according to the weight parts, mix melamine-modified phenolic resin, tung oil-modified phenolic resin, triethanolamine, 2-methylimidazole, and ethylene glycol monomethyl ether, stir at 600 rpm for 1 hour, then add the other components, stir at 1000 rpm for 2 hours to obtain the phenolic resin solution for copper-clad laminate;

[0040] S2. Immerse bleached wood pulp paper in the phenolic resin solution for copper-clad laminates obtained in step S1, and bake at 170°C for 1 minute to obtain a semi-cured sheet.

[0041] S3. Stack the 6 semi-cured sheets obtained in step S2 together to obtain a laminate. Cover the upper and lower surfaces of the laminate with a copper foil and place it in a hot press at 160°C and 30MPa pressure for 80 minutes to obtain a copper-clad laminate.

[0042] Example 3

[0043] The phenolic resin adhesive for copper clad laminates is made from the following components in parts by weight: 33 parts melamine-modified phenolic resin, 21 parts tung oil-modified phenolic resin, 8 parts triethanolamine, 0.3 parts 2-methylimidazole, 4.2 parts 3-chloro-4-difluoromethoxyphenyl isocyanate, 19 parts alumina with an average particle size of 2.6 μm, 9 parts toughening agent, and 72 parts ethylene glycol monomethyl ether.

[0044] The toughening agent is made by the following steps:

[0045] Zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid were mixed in a ratio of 1 mmol:0.5 mmol:120 mL:0.6 g and stirred at 200 rpm for 45 minutes to obtain a mixture. The mixture was placed in an oven and heated to 110 °C at a rate of 10 °C / hour, and then kept at that temperature for 48 hours. After cooling to room temperature, the reactant was obtained. The reactant was filtered to obtain a filter residue, which was washed three times with N,N-dimethylacetamide and then dried at 75 °C for 10.5 hours to obtain the auxiliary agent.

[0046] The application of this phenolic resin adhesive in the manufacture of copper-clad laminates includes the following steps:

[0047] S1. Weigh each component of the phenolic resin solution for copper-clad laminate according to the weight parts, mix melamine-modified phenolic resin, tung oil-modified phenolic resin, triethanolamine, 2-methylimidazole, and ethylene glycol monomethyl ether, stir at 500 rpm for 1.5 hours, then add the other components, stir at 800 rpm for 3 hours to obtain the phenolic resin solution for copper-clad laminate;

[0048] S2. Immerse the bleached wood pulp paper in the phenolic resin solution for copper-clad laminates obtained in step S1, and bake at 165°C for 1 minute to obtain a semi-cured sheet.

[0049] S3. Stack the 6 semi-cured sheets obtained in step S2 together to obtain a laminate. Cover the upper and lower surfaces of the laminate with a copper foil and place it in a hot press at 152°C and 38MPa pressure for 90 minutes to obtain a copper-clad laminate.

[0050] Example 4

[0051] The phenolic resin adhesive for copper clad laminates is made from the following components in parts by weight: 35 parts melamine-modified phenolic resin, 24 parts tung oil-modified phenolic resin, 10 parts triethanolamine, 0.5 parts 2-methylimidazole, 5 parts 3-chloro-4-difluoromethoxyphenyl isocyanate, 22 parts alumina with an average particle size of 2.6 μm, 12 parts toughening agent, and 76 parts ethylene glycol monomethyl ether.

[0052] The toughening agent is made by the following steps:

[0053] Zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid were mixed in a ratio of 1 mmol:0.5 mmol:120 mL:0.6 g and stirred at 200 rpm for 60 minutes to obtain a mixture. The mixture was placed in an oven and heated to 110 °C at a rate of 10 °C / hour, and then kept at that temperature for 48 hours. After cooling to room temperature, the reactant was obtained. The reactant was filtered to obtain a filter residue. The filter residue was washed three times with N,N-dimethylacetamide and then dried at 75 °C for 12 hours to obtain the auxiliary agent.

[0054] The application of this phenolic resin adhesive in the manufacture of copper-clad laminates includes the following steps:

[0055] S1. Weigh each component of the phenolic resin solution for copper-clad laminate according to the weight parts, mix melamine-modified phenolic resin, tung oil-modified phenolic resin, triethanolamine, 2-methylimidazole, and ethylene glycol monomethyl ether, stir at 600 rpm for 1.5 hours, then add the other components, stir at 900 rpm for 2 hours to obtain the phenolic resin solution for copper-clad laminate;

[0056] S2. Immerse bleached wood pulp paper in the copper-clad laminate phenolic resin solution obtained in step S1, and bake at 150°C for 1 minute to obtain a semi-cured sheet.

[0057] S3. Stack the 6 semi-cured sheets obtained in step S2 together to obtain a laminate. Cover the upper and lower surfaces of the laminate with a copper foil and place it in a hot press at 150°C and 40MPa pressure for 120 minutes to obtain a copper-clad laminate.

[0058] Example 5

[0059] The phenolic resin adhesive for copper clad laminates is made from the following components in parts by weight: 33 parts melamine-modified phenolic resin, 22 parts tung oil-modified phenolic resin, 8 parts triethanolamine, 0.3 parts 2-methylimidazole, 4.5 parts 3-chloro-4-difluoromethoxyphenyl isocyanate, 20 parts alumina with an average particle size of 2.6 μm, 11 parts toughening agent, and 74 parts ethylene glycol monomethyl ether.

[0060] The toughening agent is made by the following steps:

[0061] Zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid were mixed in a ratio of 1 mmol:0.5 mmol:120 mL:0.6 g and stirred at 200 rpm for 55 minutes to obtain a mixture. The mixture was placed in an oven and heated to 110 °C at a rate of 10 °C / hour, and then kept at that temperature for 48 hours. After cooling to room temperature, the reactant was obtained. The reactant was filtered to obtain a filter residue, which was washed three times with N,N-dimethylacetamide and then dried at 75 °C for 11.5 hours to obtain the auxiliary agent.

[0062] The application of this phenolic resin adhesive in the manufacture of copper-clad laminates includes the following steps:

[0063] S1. Weigh each component of the phenolic resin solution for copper-clad laminates according to the weight parts, mix melamine-modified phenolic resin, tung oil-modified phenolic resin, triethanolamine, 2-methylimidazole, and ethylene glycol monomethyl ether, stir at 500 rpm for 2 hours, then add the other components, stir at 800 rpm for 2.5 hours to obtain the phenolic resin solution for copper-clad laminates;

[0064] S2. Immerse bleached wood pulp paper in the copper-clad laminate phenolic resin solution obtained in step S1, and bake at 155°C for 1 minute to obtain a semi-cured sheet.

[0065] S3. Stack the 6 semi-cured sheets obtained in step S2 together to obtain a laminate. Cover the upper and lower surfaces of the laminate with a copper foil and place it in a hot press at 157°C and 32MPa pressure for 110 minutes to obtain a copper-clad laminate.

[0066] Comparative Example 1

[0067] The difference from Example 1 is that the melamine-modified phenolic resin in the phenolic resin adhesive for copper-clad laminates is replaced with ordinary linear phenolic resin.

[0068] Comparative Example 2

[0069] The difference from Example 1 is that the tung oil-modified phenolic resin in the phenolic resin adhesive for copper clad laminate is replaced with ordinary linear phenolic resin.

[0070] Comparative Example 3

[0071] The difference from Example 1 is that the phenolic resin adhesive for copper clad laminate does not include a toughening agent, thus eliminating the toughening agent preparation step.

[0072] Comparative Example 4

[0073] The difference from Example 1 is that the phenolic resin adhesive for copper clad laminates does not include 3-chloro-4-difluoromethoxyphenyl isocyanate.

[0074] Experiment Example 1: Flame Retardancy Test

[0075] Test reference standard / method: GB / T2406-1993 standard.

[0076] Testing instrument: Oxygen index meter.

[0077] Test subjects and objectives: Limiting oxygen index of copper-clad laminates prepared in Examples 1-5, Comparative Examples 1 and 4.

[0078] A higher limiting oxygen index indicates better flame retardancy. The test results are shown in Table 1:

[0079] Limiting oxygen index (%) Example 1 30.3 Example 2 30.8 Example 3 30.6 Example 4 29.9 Example 5 30.1 Comparative Example 1 22.4 Comparative Example 4 25.8

[0080] Table 1

[0081] As shown in Table 1, the limiting oxygen indexes of Examples 1-5 of the present invention are all relatively high, indicating that the present invention has good flame retardancy. Some components of the phenolic resin adhesive for copper-clad laminates used in Comparative Examples 1 and 4 are different from those in Example 1. Compared with Example 1, the limiting oxygen index of Comparative Example 1 is significantly lower, indicating that the melamine-modified phenolic resin used in the present invention can effectively improve the flame retardancy of the phenolic resin adhesive for copper-clad laminates and the copper-clad laminate itself. The limiting oxygen index of Comparative Example 4 is also somewhat lower, indicating that the 3-chloro-4-difluoromethoxyphenyl isocyanate used in the present invention can also improve the flame retardancy of the phenolic resin adhesive for copper-clad laminates and the copper-clad laminate itself.

[0082] Experiment Example 2: Toughness Test

[0083] Test reference standard / method: GB / T1043-2008 standard.

[0084] Testing instrument: Impact testing machine.

[0085] Test subjects and objectives: Impact strength of copper-clad laminates prepared in Examples 1-5, Comparative Examples 2 and 3.

[0086] Higher impact strength indicates better toughness. The test results are shown in Table 2:

[0087] <![CDATA[Impact strength (kJ·m -2 )]]> Example 1 8.28 Example 2 8.09 Example 3 8.17 Example 4 8.52 Example 5 8.41 Comparative Example 2 5.37 Comparative Example 3 5.54

[0088] Table 2

[0089] As shown in Table 2, the impact strength of Examples 1-5 of the present invention is relatively high, indicating that the present invention has good toughness. Some components of the phenolic resin adhesive used in Comparative Examples 2 and 3 for copper-clad laminates are different from those in Example 1. Compared with Example 1, the impact strength of Comparative Examples 2 and 3 is significantly reduced, indicating that the tung oil-modified phenolic resin and toughening agent used in the present invention can effectively improve the toughness of both the phenolic resin adhesive for copper-clad laminates and the copper-clad laminate itself.

[0090] Experiment Example 3: Peel Strength Test

[0091] Test reference standard / method: IPC-TM-650 standard.

[0092] Testing instrument: Peel strength tester, peel speed 50mm / min, peel angle 90°.

[0093] Test subjects and objectives: Peel strength of copper-clad laminates prepared in Examples 1-5 and Comparative Example 4.

[0094] The test results are shown in Table 3:

[0095] Peel strength (N / mm) Example 1 1.67 Example 2 1.53 Example 3 1.55 Example 4 1.69 Example 5 1.62 Comparative Example 4 1.03

[0096] Table 3

[0097] As shown in Table 3, the peel strength of Examples 1-5 of the present invention is relatively high. Some components of the phenolic resin adhesive used in Comparative Example 4 for copper-clad laminates are different from those in Example 1. Compared with Example 1, the peel strength of Comparative Example 4 is significantly lower, indicating that the 3-chloro-4-difluoromethoxyphenyl isocyanate used in the present invention can effectively improve the adhesion of the phenolic resin adhesive for copper-clad laminates and the peel strength of the copper-clad laminate.

[0098] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A phenolic resin adhesive for copper-clad laminates, characterized in that: It is made from the following components in parts by weight: 35 parts of melamine-modified phenolic resin, 24 parts of tung oil-modified phenolic resin, 10 parts of triethanolamine, 0.5 parts of 2-methylimidazole, 5 parts of 3-chloro-4-difluoromethoxyphenyl isocyanate, 22 parts of alumina with an average particle size of 2.6 μm, 12 parts of toughening agent, and 76 parts of ethylene glycol monomethyl ether. The toughening agent is prepared by the following steps: zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid are mixed and stirred for 40-60 minutes to obtain a mixture. The mixture is placed in an oven, heated to 110°C and kept at that temperature for 48 hours. After cooling to room temperature, a reactant is obtained. The reactant is filtered to obtain a filter residue. The filter residue is washed three times with N,N-dimethylacetamide and dried for 10-12 hours to obtain the toughening agent. In the preparation steps of the toughening agent, the ratio of zinc nitrate, 3-bromo-2,6-dimethylbenzoic acid, N,N-dimethylacetamide, and benzoic acid is 1 mmol:0.5 mmol:120 mL:0.6 g. The stirring speed is 200 rpm, the heating rate of the oven is 10 °C / hour, and the drying temperature is 75 °C.

2. The application of the phenolic resin adhesive for copper-clad laminates according to claim 1 in the manufacture of copper-clad laminates.

3. The application according to claim 2, characterized in that: Includes the following steps: S1. Weigh each component of the phenolic resin solution for copper-clad laminates according to the weight parts, mix melamine-modified phenolic resin, tung oil-modified phenolic resin, triethanolamine, 2-methylimidazole, and ethylene glycol monomethyl ether, stir at 500-600 rpm for 1-2 hours, then add the other components, stir at 800-1000 rpm for 2-3 hours to obtain the phenolic resin solution for copper-clad laminates; S2. Immerse the bleached wood pulp paper in the phenolic resin solution for copper-clad laminates obtained in step S1, and bake at 150-170℃ for 1 minute to obtain a semi-cured sheet. S3. Stack the 6 semi-cured sheets obtained in step S2 together to obtain a laminate. Cover the upper and lower surfaces of the laminate with a copper foil and place it in a hot press at 150-160℃ and 30-40MPa pressure for 80-120 minutes to obtain a copper-clad laminate.