JPS6345698B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention particularly relates to a cellulose-based unsaturated polyester resin electrical laminate having excellent punching workability and moisture resistance, and a method for producing the same. The electrical laminate used in the present invention refers to a laminate or a copper-clad laminate that is used as a substrate for various metal foil parts, for example, and the shape of the electrical laminate is a plate with a thickness of approximately 0.5 to 5 mm. say. The above laminate is manufactured by impregnating a cellulose base material with an unsaturated polyester resin, then laminating and curing the impregnated cellulose base material. For example, the present invention has already proposed in JP-A-55-4838, JP-A-55-53013, etc. a method for continuously manufacturing electrical laminates using unsaturated polyester resin that is liquid at room temperature. . In addition, examples of manufacturing laminates by heat and pressure molding using unsaturated polyester resins that are solid at room temperature include JP-B No. 48-29625, JP-A No. 51-111885, JP-A No. 52-92288, etc. There are some proposals, but these have not yet reached the stage of practical application. Cellulose-based unsaturated polyester resin laminates obtained by the above method have extremely good electrical insulation properties, soldering heat resistance, mechanical strength, etc. under normal conditions, but due to moisture absorption, these laminates cannot be used as electrical laminates. It has the disadvantage that the deterioration of characteristics is often large. Although the unsaturated polyester resin itself has excellent electrical insulation, heat resistance, and moisture resistance, it has poor adhesion to the cellulose that makes up the base material, and the interface between the resin and cellulose fibers peels due to moisture absorption. As a result, the amount of moisture absorbed increases,
This is thought to be due to the fact that this leads to a decline in various performances. As an attempt to improve these drawbacks, a method has already been proposed in which a cellulose base material is treated with an initial condensate of an amino organic compound (Japanese Patent Publication No. 13781/1983). By the way, the present inventors also pre-treated a paper base material with these initial condensates, created a laminate from it and an unsaturated polyester resin, and investigated the performance. There is little deterioration in electrical insulation properties and soldering heat resistance, and considerable improvements are seen in terms of moisture resistance and water resistance.
On the other hand, it was easy to crack due to impact, so the punching workability of this material was not at all practical. It is believed that the punching processability is greatly influenced by the physical properties of the unsaturated polyester resin used, and the present inventor used paper that had undergone the above-mentioned pretreatment and examined a large number of unsaturated polyester resins on the market. However, there were none that had good punching workability and were of practical use. In view of this current situation, the present inventors have conducted extensive research and have found that soft thermoplastic resins are used for the purpose of imparting flexibility to amino resins such as melamine resins and guanamine resins used in the pretreatment of cellulose base materials. The present inventors have discovered that by adding this material, the resulting laminate has excellent punching workability and exhibits less deterioration in electrical insulation properties, heat resistance, mechanical strength, etc. when absorbing moisture, and has completed the present invention. . The present invention will be explained in detail below. The amino resin referred to in the present invention refers to melamine resin,
Refers to guanamine resin, urea resin, cyclic urea resin, etc.; representative examples include guanamines such as melamine, formoguanamine, acetoguanamine, propioguanamine, benzoguanamine, and adipodiguanamine, and cyclic ureas such as urea, ethylene urea, and propylene urea. It refers to an initial condensation product of an amino compound and an aldehyde such as formaldehyde, or a product in which part or all of the methylol group thereof is etherified with a lower alcohol such as methanol or butanol. However, among the aldehydes, formaldehyde is most preferred. Furthermore, in the present invention, two or more of the above-mentioned resins may be used as a mixture or co-condensed. Furthermore, a compound containing a methylol group such as a phenol resin or N-methylol acrylamide may be mixed or co-condensed. However, among them, melamine resin and/or guanamine resin are most preferable in terms of performance such as heat resistance and moisture resistance. Examples of the soft thermoplastic resin added to the above amino resin for the purpose of improving punching workability include the following. That is, (a) methyl acrylate, ethyl acrylate,
Alkyl acrylates having an alkyl group having 1 to 14 carbon atoms such as butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate; or polymers consisting of alkyl methacrylates having an alkyl group having 6 to 16 carbon atoms such as lauryl methacrylate and octadecyl methacrylate. as a main component and copolymerizable with them, such as methyl methacrylate, ethyl methacrylate, acrylonitrile, acrylic acid, methacrylic acid, acrylamide, methacrylamide, dimethylaminoethyl methacrylate, methylol acrylamide, butoxymethyl acrylamide, hydroxyethyl acrylate, hydroxyethyl methacrylate, A soft acrylic polymer consisting of various acrylic compounds such as hydroxypropyl methacrylate and glycidyl methacrylate, and vinyl compounds such as styrene, vinyl acetate, vinyl chloride, dibutyl maleate, maleic anhydride, and itaconic acid. (b) Homopolymers of conjugated dienes such as butadiene, isoprene, and chloroprene, or conjugated diene copolymers of butadiene-styrene, butadiene-acrylonitrile, butadiene-methyl methacrylate, or the above (a)
A soft conjugated diene polymer made by copolymerizing various acrylic compounds and/or vinyl compounds mentioned in the section. (c) Saponified products of polyethylene, polyisobutylene, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, or copolymerized products containing ethylene as the main component and various monomers mentioned in the above (a). Soft olefin polymer. (d) Polyvinyl acetate or copolymerization of vinyl acetate as a main ingredient with various monomers listed in (a) above, or saponified products thereof, polyvinyl alcohol obtained by saponifying polyvinyl acetate. , polyvinyl acetal resin such as polyvinyl formal obtained by further acetalizing it. Incidentally, the term "copolymerized or so-and-so-based resin" as used in the present invention means those polymerized by means such as random, block, and graft methods, and also includes two or more ternary resins. Furthermore, there are no limitations on the polymerization methods such as emulsification, solution, suspension, block, and others. (e) A soft alkyd resin made from polybasic acids and polyhydric alcohols. Polybasic acids include phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, sebacic acid,
Azelaic acid, succinic acid, dimer acid; polyhydric alcohols include ethylene glycol, diethylene glycol, 1,4-butanediol,
Consisting of 1,5-pentanediol, glycerin, trimethylolpropane, pentaerythritol, etc., modified with other fats and oils, rosin acid, etc. as necessary. (f) Examples include soft polyamide resins made from the above-mentioned polybasic acids and polyvalent amino compounds such as ethylenediamine, triethylenediamine, and hexamethylenediamine. In the present invention, the thermoplastic resin to be added to the amino resin to improve punching workability must be a thermoplastic resin with a softening point of 30°C or less, more preferably 0°C or less, in order to fully exhibit its effect. Preferably, it is a resin. Also, among thermoplastic resins that meet the above conditions, one or two functional groups such as a carboxyl group, a hydroxyl group, an amino group, an amide group, a methylol group, an epoxy group, etc. that can be condensed with the methylol group of an amino resin are included in the molecule. A material having at least three is preferable for the present invention, since the mechanical strength and heat resistance of the finally obtained laminate are less likely to deteriorate. In this sense, alkyd resins having a carboxyl group or hydroxyl group at the end, and polyamide resins having a carboxyl group or amino group at the end are preferable. Also, in soft acrylic polymers, conjugated diene polymers, olefin polymers, and vinyl acetate polymers, functional monomers are used to introduce the above-mentioned functional groups into the molecular chains or at the ends. It is desirable to copolymerize the bodies. Usually, to introduce a carboxyl group, acrylic acid, methacrylic acid, maleic anhydride,
For introducing monomers such as itaconic acid, amino groups and amide groups, dimethylaminoethyl methacrylate, acrylamide, methacrylamide, etc. For introducing hydroxyl groups, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2 -Hydroxypropyl methacrylate, etc.
To introduce a methylol group, methylol acrylamide or the like is used, and to introduce an epoxy group, glycidyl methacrylate or the like is used. According to studies conducted by the present inventors, when a soft acrylic copolymer or a conjugated diene copolymer obtained by copolymerizing these functional monomers is added to an amino resin, the resulting laminate It has also become clear that this material is a suitable embodiment of the present invention because it has well-balanced properties such as punching workability, electrical insulation properties under normal conditions and under moisture absorption, heat resistance, and mechanical strength. By the way, the optimal amount of the soft thermoplastic resin to be added to the amino resin varies depending on the glass transition temperature of the unsaturated polyester resin used in the laminate, but it is usually used for 100 parts by weight of the amino resin. It is preferably within the range of 3 parts by weight to 40 parts by weight.
If the amount used is less than 3 parts by weight, the effect of improving punching workability will be small, and if it exceeds 40 parts by weight, mechanical strength, heat resistance, etc. will be greatly reduced when made into a laminate. As for how to use it, you can mix a solution or suspension of a soft thermoplastic resin with a solution of an amino resin, or add a solution or suspension of a soft thermoplastic resin at the stage of manufacturing the amino resin. You can. Water, alcohols, ketones, esters, etc. are used as the solvent. In addition, the concentration of these treatment agents should be adjusted so that the total amount deposited on the cellulose fiber base material after drying is 3 to 30 parts by weight, preferably 6 to 20 parts by weight, based on the weight of the dry base material. Desirably, if the amount is less than 3 parts by weight, the effect will not be sufficient, and if it exceeds 30 parts by weight, the plate will become brittle when made into a laminate and the punching workability will deteriorate. A solution or suspension of the treatment agent prepared under the above conditions is coated with a cellulose paper base such as kraft paper or linter paper, or in some cases a cellulose yarn fabric base such as cotton or rayon, using a dipping bath, roll coater or After impregnation using a spray or the like, a treated substrate is obtained by drying to remove the solvent. The desirable drying temperature is usually 50 to 170°C, and the drying time is about 0.5 to 60 minutes. On the other hand, in the unsaturated polyester resin used in the present invention, the structural formula of the unsaturated polyester chain is, for example, Well-known and flame-retardant alcohols containing halogen or the like in their structures can be used. Therefore, polyhydric alcohols used as raw materials include ethylene glycol, propylene glycol, diethylene glycol, 1,4- Butanediol and 1,5-pentanediol, bisphenol A-
Propylene oxide adduct, 2,2-dipromoneopentyl glycol, saturated polybasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, azelaic acid, chlorendoic acid, tetrabromophthalic anhydride, tetrachloro Commonly used phthalic anhydride and unsaturated polybasic acids are maleic anhydride and fumaric acid, and are a mixture of these and a crosslinking monomer.
Further, a mixture of an epoxy-acrylate having two or more acryloyl groups or methacryloyl groups at the molecular end and a crosslinking monomer, which is generally called a vinyl ester resin, can also be applied to the present invention. Styrene is commonly used as a crosslinking monomer, but other examples include α-methylstyrene, vinyltoluene, chlorostyrene, divinylbenzene, alkyl acrylates having 1 to 10 carbon atoms, alkyl methacrylates having 1 to 10 carbon atoms, and phthalic acid. Monomers such as diallyl and triallyl cyanurate can also be used. The amount of these crosslinking monomers used is
20-50% by weight of unsaturated polyester resin,
Furthermore, a general-purpose organic peroxide is added as a curing catalyst, and a curing accelerator is added as necessary during curing. In addition, the curing catalyst is not limited to these,
All known curing catalysts can be used together with organic peroxides or alone, such as curing catalysts that are sensitive to light, radiation, or electron beams. Further, depending on the purpose, flame retardants, flame retardant aids, polymerization inhibitors, ultraviolet absorbers, fillers, colorants, etc. may be added to the unsaturated polyester resin liquid. An electrical laminate can be produced by impregnating the treated base material with the unsaturated polyester resin liquid, laminating the resin-impregnated base materials, and curing the resin-impregnated base materials. At this time, the unsaturated polyester resin is preferably liquid at room temperature, and has a viscosity of 0.1 to 30 poise, more preferably 0.5 to 15 poise. Furthermore, there is no restriction on the molding pressure when laminating and curing the base materials impregnated with unsaturated polyester resin, but the present inventors have already reported in JP-A-55-53013
As proposed in 2007, superior performance laminates can be obtained by curing under substantially no pressure, which is a preferred embodiment of the present invention. Note that the punching workability of the laminate obtained from the treated base material of the present invention is excellent, but in order to make low-temperature punching workability possible, the glass transition temperature of the cured product of the unsaturated polyester resin must be 20 It is preferable to use resins at ~80°C. The laminates and metal foil-clad laminates produced by the above method have excellent punching workability and moisture resistance, and can be used as electrical laminates for various purposes such as printed circuit boards. Next, the present invention will be explained in more detail with reference to Examples. Example 1 100 parts by weight of water (hereinafter abbreviated as parts), melamine resin (Nippon Carbide Industries, Nikaresin S-305)
8 parts of methylol group-containing water-soluble acrylic ester (Soken Chemical, WS-120) was added to a treatment solution consisting of 3 parts of 285 μm thick kraft paper (Tomoekawa Paper Co., Ltd.).
MKP-150) was immersed, taken out, and the excess liquid was squeezed out using a roll, and then heated at 120°C for 10 minutes to obtain a treated paper base material with a coating weight of 14.6%. On the other hand, an unsaturated polyester polymer made of diethylene glycol, isophthalic acid, and maleic anhydride as raw materials, with a molar ratio of each raw material component of 3:2:1, an average molecular weight of about 3900, and a condensation process using a general method. 1 part of 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane (Perhexa 3M, Nippon Oil & Fats) was added as a curing catalyst to a resin liquid consisting of 62 parts of styrene and 38 parts of styrene. This resin solution was impregnated into the above treated paper, five sheets were laminated, and at the same time a 35μm electrolytic copper foil coated with epoxy adhesive was laminated, and the paper was cured at 100℃ for 45 minutes under virtually no pressure to form a 1.6mm sheet.
A single-sided copper-clad board was obtained. Its performance is shown in Table 1. Example 2 100 parts of melamine and 210 parts of 37% formalin were placed in a reactor, made alkaline to pH 9, and heated to 15% while stirring.
The temperature was raised to 90℃ over 30 minutes at the same temperature.
The reaction continued for minutes. Next, 64 parts of water-soluble acrylic acid ester (WS-120) was added, and the mixture was reacted at the same temperature for an additional 10 minutes, and then cooled to room temperature. Kraft paper with a thickness of 285 μm was immersed in a treatment agent solution consisting of 100 parts of water and 17 parts of the modified melamine resin described above, and a treated paper base material with a coating weight of 14.0% was obtained in the same manner as in Example 1. Next, the same operations as in Example 1 were performed using the obtained treated paper to obtain a copper-clad laminate having a thickness of 1.6 mm. Its performance is shown in Table 1. Example 3 100 parts of water, melamine resin (Nica Resin S-305)
8 parts, acrylic acid ester emulsion with methylol group (Nippon Carbide Industries, Nikazol)
RX-18A) Prepare a processing agent solution consisting of 3 parts,
A treated paper base material with a coating weight of 13.4% was obtained in the same manner as in Example 1. A 1.6 mm copper-clad laminate was obtained from this treated paper in the same manner as in Example 1. Its performance is the first priority.
Shown in the table. Example 4 100 parts of water, melamine resin (Nica Resin S-305)
A treatment agent solution consisting of 8 parts and 3 parts of a modified NBR latex containing a carboxyl group (Nippon Zeon, Nippor 1571) was prepared, and a treated paper base material with a coating amount of 13.8% was prepared in the same manner as in Example 1. Using this treated paper, the same operations as in Example 1 were carried out to obtain a 1.6 mm copper-clad laminate. Its performance is shown in Table 1. Example 5 In Example 4, a 1.6 mm copper-clad laminate was made by using unmodified NBR latex (Nippon Zeon, Nitzpol 1551) without functional groups instead of modified NBR latex containing carboxyl groups. Created. Its performance is shown in Table 1. The amount of treatment agent attached to the treated paper was 13.6%. Example 6 100 parts of water, melamine resin (Nica Resin S-305),
A treated paper base material with a coating weight of 14.6% was obtained by the method of Example 1 using a treatment agent solution consisting of 3 parts of a water-soluble alkyd resin (Nissaku Arrow Chemical Co., Ltd., Aloron 376). Next, with the obtained treated paper, Example 1
A copper-clad laminate with a thickness of 1.6 mm was created by performing the same operation as above. Its performance is summarized in Table 1. Example 7 A long treated paper base material was prepared in advance by continuously immersing 285 μm thick kraft paper in the same treatment agent solution as in Example 3 and heating and drying it at 120° C. for 6 minutes. While continuously transporting five sheets of this treated paper, the same resin liquid as in Example 1 was impregnated from the top surface of each sheet, and then they were overlapped using two pairs of rolls, and a 35 μm sheet coated with epoxy adhesive from one side was Electrolytic copper foil is laminated with a 50 μm thick polyester film on the opposite side, and the temperature is
It was continuously transferred to a tunnel type hot air drying oven at 110°C, and was heated and cured for 15 minutes. After cutting this material, it was further heat-treated at 160℃ for 10 minutes.
Finally, a copper-clad laminate with a thickness of 1.6 mm was obtained. Table 1 shows the performance of the obtained laminate. Comparative example: 8 parts of melamine resin (Nicaresin S-305), water
A piece of kraft paper with a thickness of 285 μm was immersed in a treatment agent solution containing 100 parts, and the amount of adhesion was determined in the same manner as in Example 1.
A 11.2% melamine resin treated paper was obtained. Using this treated paper, the same operation as in Example 1 was performed to obtain a thickness of 1.6 mm.
A copper-clad laminate was obtained. This performance is shown in Table 1 for comparison with the present invention.

[Table] Punching workability was based on ASTM-D617, and water absorption, insulation resistance, and soldering heat resistance were based on JIS-C6481.

Claims (1)

[Scope of Claims] 1. In an electrical laminate made of a cellulose base material and an unsaturated polyester resin, the cellulose base material is pre-impregnated with an amino resin to which a soft thermoplastic resin is added and then treated with an unsaturated polyester resin. An unsaturated polyester resin electrical laminate that is impregnated with saturated polyester resin, laminated and cured. 2. The unsaturated polyester resin electrical laminate according to claim 1, wherein the soft thermoplastic resin is a soft thermoplastic resin having a functional group capable of condensing with an amino resin. 3 A soft thermoplastic resin having a functional group capable of condensing with an amino resin has one or more selected from the group consisting of a carboxyl group, a hydroxyl group, an amino group, an amide group, a methylol group, and an epoxy group in its molecule. The unsaturated polyester resin electrical laminate according to claim 2, which is a soft acrylic polymer. 4 A soft thermoplastic resin having a functional group capable of condensing with an amino resin has one or more selected from the group consisting of a carboxyl group, a hydroxyl group, an amino group, an amide group, a methylol group, and an epoxy group in its molecule. The unsaturated polyester resin electrical laminate according to claim 2, which is a soft conjugated diene-based polymer. 5. The unsaturated polyester resin electrical laminate according to any one of claims 1 to 4, wherein the amino resin is a melamine resin and/or a guanamine resin. 6. The unsaturated polyester resin electrical laminate according to any one of claims 1 to 5, wherein the unsaturated polyester resin has a glass transition temperature of 20 to 80°C as a cured product. 7 A cellulose base material is pre-impregnated with an amino resin to which a soft thermoplastic resin has been added, and after drying by heating, the treated cellulose base material is impregnated with an unsaturated polyester resin liquid, and then laminated. A method for producing an unsaturated polyester resin electrical laminate, characterized in that the unsaturated polyester resin electrical laminate is cured under substantially no pressure conditions. 8. The method according to claim 7, wherein the soft thermoplastic resin is a soft thermoplastic resin having a functional group capable of condensing with an amino resin. 9 A soft thermoplastic resin having a functional group capable of condensing with an amino resin has one or more selected from the group consisting of a carboxyl group, a hydroxyl group, an amino group, an amide group, a methylol group, and an epoxy group in its molecule. 8. The method according to claim 7, wherein the soft acrylic polymer has the following properties. 10 A soft thermoplastic resin having a functional group that can be condensed with an amino resin has a carboxyl group,
One or two selected from the group consisting of hydroxyl group, amino group, amide group, methylol group, and epoxy group
8. The method according to claim 7, which is a soft conjugated diene polymer having at least one of the following. 11 Claims 7 to 1, wherein the amino resin is a melamine resin and/or a guanamine resin
The method described in any of item 0. 12. The method according to any one of claims 7 to 11, wherein the unsaturated polyester resin has a cured product having a glass transition temperature of 20 to 80°C.