JPH05222676A - Fixing agent for preventing fray of woven glass fiber fabric - Google Patents

Abstract

PURPOSE:To provide a fixing agent for preventing the fray of woven glass fiber fabric, effective in firmly bonding glass fibers when applied to the cut edge of a woven glass fiber fabric to prevent the fray of the edge warp and resistant to swell with solvent of a thermosetting resin varnish. CONSTITUTION:The objective fixing agent for preventing the fray of woven glass fiber fabric contains 100 pts.wt. of a bisphenol-type epoxy resin, 2-10 pts.wt. of an imidazole-type and/or t-amine-type cure accelerators and 2-20 pts.wt. of a reactive flexibilizer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-fray adhesive agent for glass fiber fabrics, and more particularly to an anti-fray adhesive agent for glass fiber fabrics woven by an air jet loom or the like used for copper clad laminates.

[0002]

2. Description of the Related Art Although glass fiber woven fabrics were mostly woven by shuttle looms in the past, the proportion of those woven by unknitted looms such as air jet looms has recently been increasing. Particularly in the field of copper clad laminates that consume a large amount of glass fiber fabric, most of them are woven by an air jet loom. However, in the case of the air jet loom, the weft yarn is cut after each weft insertion, so that the cut ends of the weft yarn are present at both ends of the fabric in a tufted shape. As is well known, a glass fiber woven fabric used for a copper clad laminate is impregnated with a thermosetting resin varnish such as an epoxy resin and then dried to obtain a prepreg. A copper clad laminate is obtained by laminating a plurality of these prepregs, laminating copper foils, and heating and pressing.

When a prepreg is manufactured from a glass fiber woven fabric having tassels woven by a straight loom such as an air jet loom, the following problems occur.

The first problem is that the glass fiber woven fabric contains an excessive amount of resin in the ears, and the ears tend to be thicker than other parts. Is. When prepregs with thick ears are cut to the required length and piled up, the height of the layers of the prepregs piled up becomes higher because the locations where the ears are present are higher. I can't do it. Such a prepreg having a non-uniform thickness over the entire width causes various inconveniences when a product is made using the prepreg. For example, when obtaining a copper clad laminate using a prepreg, there is a drawback that the entire prepreg width cannot be pressed.

A second problem is that when the shapes of both ends of the width of the prepreg are viewed in the length direction, the prepreg is not straight but has irregularities due to the ears. When these prepregs with irregularities at both ends are cut to a certain length and piled up, there is a drawback that the edges are difficult to align, and when the edges are further aligned, a part of the irregularities scatters and breaks into the prepreg. If mixed, it will cause defective products.

[0006] The third problem is that the glass fibers in the tassels are cut off during prepreg production,
It is mixed in the varnish and adheres to the surface of the prepreg to cause defective products. Although the problems when the prepreg is manufactured from the glass fiber woven fabric having the tassels have been described above, the first problem may similarly occur in the ears of the glass fiber woven fabric woven by the shuttle loom.

In order to avoid the first and second problems, a method in which the ears are cut and removed after manufacturing the prepreg can be adopted, but in this case, the third problem cannot be avoided, and the glass fiber fabric is also unavoidable. And the yield of the varnish decreases, which is not preferable in terms of cost.

[0008] Furthermore, it is also conceivable to remove the ear portion before making the glass fiber fabric into a prepreg, and some proposals have been made. For example, a method of fusing the selvages with a laser beam and welding the cut ends at the same time, or weaving thermoplastic resin threads into the warp selvages of the glass fiber fabric, and then weaving the thermoplastic resin thread parts. There is a method of heat fusion. However, the method using a laser beam has not been put into practical use because it is not possible to increase the speed of fusing and there is a problem that small balls generated during fusing fall into the varnish during the prepreg process. The method of weaving thermoplastic resin threads into the warp selvages has a problem that it cannot be applied to a special woven fabric because it cannot carry out heating deoiling, which is a normal process for manufacturing glass fiber woven fabrics.

Further, it has been proposed to solve the above problems by applying a hot melt type adhesive to the inner part of the ear of the glass fiber fabric. However, in the case of the hot melt type, in the prepreg process, since the solvent is heated at a temperature of around 150 ° C., depending on the conditions, troubles such as warping of the end warp and entanglement with the rollers of the prepreg device occur. There was something to do. In addition, since the coated edge becomes a little thick, if you cut it to a certain size after stacking it and stack it,
There is also a problem that both end portions are higher than the central portion, which is an obstacle to automation of the laminating process.

[0010]

SUMMARY OF THE INVENTION A first object of the present invention is that when applied to the cut end of a glass fiber woven fabric, the adhesion of the glass fibers is strong and the warp at the end is not frayed, Another object of the present invention is to provide an anti-fraying adhesive agent for glass fiber fabrics, which does not swell in the solvent used for the thermosetting resin varnish. A second object of the present invention is to make a prepreg by impregnating a thermosetting resin varnish with a glass fiber woven fabric having anti-fraying adhesive applied to the cut ends of both ears, and having a uniform thickness over the entire width, A glass fiber woven fabric that has a straight shape at both ends of the width, has no unevenness in the lateral direction, and is capable of obtaining a prepreg in which the glass fiber at the end is not damaged and adheres to other parts to deteriorate the quality. To provide.

[0011]

[Means for Solving the Problems] An anti-fraying adhesive agent for glass fiber fabric which achieves the first object of the present invention, comprises 100 parts by weight of a bisphenol type epoxy resin, imidazole type and / or tertiary amine type curing accelerator. It is characterized by containing 2 to 10 parts by weight of the agent and 2 to 20 parts by weight of the reactive flexibility-imparting agent. The glass fiber woven fabric that achieves the second object of the present invention is characterized in that the above-mentioned anti-fray adhesive agent is applied in a constant width of both ears in an amount of 5% to 10% based on the weight of the glass fiber woven fabric. And

The epoxy resin used in the anti-ravel adhesive of the present invention is limited to bisphenol type epoxy resin. As bisphenol type epoxy resin, bisphenol A type and bisphenol F
Any of the types may be used, but the bisphenol A type is preferred. The bisphenol type epoxy resin preferably has an epoxy equivalent of 150 to 1000 and a molecular weight of 900 to 2000. The reason is,
If the epoxy equivalent or molecular weight is smaller than this range, the epoxy resin easily spreads beyond the applied area due to the capillary phenomenon in the state before the solvent evaporates in the heating process after application and the curing reaction begins. As will be described later, the application amount of the anti-raveling adhesive is 5 with respect to the weight of the fabric.
%, The adhesive strength between the glass fiber yarns is not sufficient to obtain a sufficient anti-raveling effect, because it is limited to the range of 10% to 10%.
On the other hand, when the epoxy equivalent or the molecular weight is larger than this range, it is difficult to obtain the effect of adding the flexibility-imparting agent, the applied portion becomes brittle, and it is easy to crack or break due to impact.

The curing accelerator of the epoxy resin used in the anti-raveling adhesive of the present invention is limited to those of imidazole type and / or tertiary amine type. The anti-fray adhesive of the present invention is prepared and applied at room temperature, and dried and cured by heating. Therefore, what is required of the curing accelerator used is that the pot life at room temperature is long and the curing reaction upon heating is completed in a short time.
As a guide for the curing time, the heating temperature is 150 ° C to 200 ° C.
It is 30 seconds to 5 minutes in case of ° C. As a result of studying such conditions, it was found that imidazole-based and tertiary amine-based curing accelerators satisfy this condition. Examples of the imidazole-based curing accelerator include imidazole itself, benzimidazole, 2-aminobenzimidazole, and 2
-Methylbenzimidazole, 5-methylbenzimidazole and the like can be mentioned. Examples of the tertiary amine-based curing accelerator include benzyldimethylamine and α-methylbenzyldimethylamine. These curing accelerators may be used alone or in combination of plural kinds. The amount of the curing accelerator used is 2 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin. The reason for this is that if the amount used is less than this range, the curing reaction is not carried out sufficiently and the effect of preventing fraying is weakened, whereas if the amount used is more than this range, the pot life becomes short, which is inconvenient.

The anti-raveling sticking agent of the present invention contains a reactive flexibility-imparting agent as an essential component. When only the epoxy resin is used as a component, there is a problem that the portion coated with the adhesive becomes too hard and the life of the slitter blade is short, so that the slitter cannot be cut immediately. Further, the applied portion becomes brittle, and is easily broken or cracked by impact. Therefore, a reactive flexibility-imparting agent is added to impart flexibility to the coating film of the anti-raveling adhesive. Although there are various types of flexibility-imparting agents for epoxy resins, plasticizer-based flexibility-imparting agents are not preferred because they are dissolved in the resin varnish during the prepreg step and adversely affect the resin varnish. Therefore, a flexibility-imparting agent that reacts with the epoxy resin must be selected. Examples of the reactive flexibility-imparting agent used in the anti-raveling adhesive of the present invention include (i) polyalkylene glycols such as polyethylene glycol and polypropylene glycol (suitable molecular weight is 500 to 800), and (ii) poly Diglycidyl ether of alkylene glycol, (iii) dimer acid type, trimer acid type epoxy resin and the like can be used. The reactive flexibility-imparting agent is added in an amount of 2 to 20 parts by weight based on 100 parts by weight of the epoxy resin. The reason is that if the addition amount is less than 2 parts by weight, the effect of imparting flexibility is not sufficiently obtained, and if the addition amount is more than 20 parts by weight, the flexibility becomes too large, and the anti-raveling agent is used. This is because the effect decreases. The molecular weight of the polyalkylene glycol is preferably 500 to 800 as described above, because the molecular weight of less than 500 is not sufficient to provide the flexibility-imparting effect, while the molecular weight of more than 800 is insufficient to prevent the fraying. It will be enough.

The anti-fraying adhesive of the present invention is used in a state in which the above-mentioned essential components are dissolved in an organic solvent. The solvent is not particularly limited, but any one commonly used as a solvent for epoxy resins such as ketones such as acetone and methyl ethyl ketone, cellosolves such as methyl cellosolve, and saturated hydrocarbons such as n-hexane. Can be used. However, in consideration of handleability and subsequent drying, it is desirable that the boiling point is about 50 ° C to 140 ° C. It is possible to mix not only one kind of solvent but also a plurality of kinds. It is desirable that the amount of the solvent be 5 to 10 times the weight of the epoxy resin. The anti-fray adhesive agent solution thus prepared is applied to the anti-fray portion of the glass fiber fabric. The coating amount is set so that the solid content of the anti-fray adhesive agent is 5 to 10% with respect to the weight of the glass fiber woven fabric. A roller method is preferable as the application method, but a brush method or the like is also possible. The position where the anti-raveling adhesive is applied may be any position as long as it is a position to prevent the fraying of the glass fiber woven fabric, but it is not possible to use a tassels woven by an air jet loom used for copper clad laminates. In the case of the glass fiber woven fabric that it has, the inside of both ears is about 10 m
It is preferable to apply the m-width in the warp direction.

The glass fiber fabric coated with the anti-raveling adhesive is continuously introduced into the heating section, the solvent is dried,
Further, a curing reaction of the anti-fray adhesive mainly composed of epoxy resin is performed. The heating conditions in this case vary depending on the kind and amount of the solvent and the kind and addition amount of the curing accelerator, but the heating temperature is 150 to 200 ° C. and the heating time is 30.
The condition can be selected within the range of seconds to 5 minutes. It is necessary that the curing reaction has progressed by 90% or more when heating is completed. After the heating, the glass fiber woven fabric is further cut by a slitter at approximately the center of the anti-fray adhesive applied to a width of about 10 mm. This cutting takes place simultaneously on both ears of the fabric. Therefore, the cut glass fiber woven fabric is in a state where the anti-fraying adhesive having a width of about 5 mm is applied to both ends, and the ears including the tufted ears are removed from the woven fabric.

As the woven fabric to which the anti-raveling adhesive is applied in the present invention, it is desirable to use a glass fiber woven fabric which is deoiled after weaving and further treated with a surface treating agent such as a silane coupling agent. After oiling, the anti-raveling treatment may be performed before the surface treatment, and the surface treatment may be performed thereafter. In the case of a woven fabric made of glass yarn that uses a degreasing-free sizing agent, which is used in some cases, the degreasing process is not necessary and the surface treatment agent is also included in the sizing agent. No process is required. Therefore, the glass fiber woven fabric after the weaving can be subjected to the anti-raveling treatment.

[0018]

The anti-fray adhesive of the present invention comprises a bisphenol type epoxy resin as an epoxy resin, an imidazole compound and / or a tertiary amine compound as a curing accelerator, and the above bisphenol as a flexibility-imparting agent. It uses a flexibility-imparting agent that reacts with a type epoxy resin. Since the bisphenol type epoxy resin has a bisphenol F or bisphenol A structure in which the benzene ring is strongly bonded by a methylidene group or an isopropylidene group, it has excellent adhesiveness and chemical resistance, and has a fray-preventing effect which is excellent as a fray-preventing adhesive. Provides solvent resistance. The imidazole-based compound and the tertiary amine-based compound as a curing accelerator contribute to shortening the curing time by heating while lengthening the pot life at room temperature, and when continuously treating the glass fiber fabric. The processing speed can be increased. Furthermore, the reactive flexibility-imparting agent contributes to the improvement of the flexibility of the coating film of the anti-raveling adhesive.

The glass fiber woven fabric to which the anti-raveling adhesive of the present invention is applied at both ends does not have the ears of a usual woven fabric, and the warp yarns of the base portion are the end portions. However, since the anti-raveling adhesive having a width of at least about 5 mm is applied to this portion, the warp does not fray. Further, since the anti-raveling adhesive has flexibility, the portion to which the anti-raveling agent is applied is not cracked or broken. In the glass fiber woven fabric of the present invention, the application amount of the anti-raveling adhesive agent on both ends thereof is in the range of 5% to 10% with respect to the glass fiber woven fabric. There is almost no difference in the thickness with. Therefore, when the epoxy resin varnish is impregnated with the glass fiber woven fabric of the present invention to prepare a prepreg, which is cut to a certain size and stacked, a difference in height between the central portion and both end portions is hardly seen.

[0020]

The present invention will be further described with reference to the following examples. <Example 1> (1). The following components (a), (b), (c) and (d)
Was used to prepare an anti-fray sticker solution. (A) Bisphenol A type epoxy resin Epicoat 1001 100 parts by weight (Yukaka Shell Co., Ltd. epoxy equivalent 450-500 molecular weight 900) (b) Curing accelerator imidazole 2 parts by weight (c) Flexibility imparting agent Polyethylene glycol ( Molecular weight: 600) 4 parts by weight (d) Solvent Methyl cellosolve 1000 parts by weight (2). The anti-fray adhesive obtained above was applied to a glass fiber woven fabric with a roller coater in a width of 10 mm along the warp direction, and then dried and cured at 160 ° C. for 3 minutes.
The coating amount was 5.8% based on the glass fiber woven fabric. Glass fiber fabric is WEA18W BZ manufactured by Nitto Boseki Co., Ltd.
2 (plain weave, thickness 0.18 mm, epoxy silane treatment)
It was used. (3). The central portion of the portion of the glass fiber woven fabric obtained above, to which the anti-fraying adhesive is applied, is cut along the warp, and the tensile adhesive strength is measured with one of the warp threads at the outermost end, and the ear fray strength and the did. Further, the glass fiber fabric coated with the anti-raveling adhesive agent obtained above was immersed in various solvents for 72 hours (25 ° C.), and the state of the anti-raveling adhesive agent applied portion was observed to evaluate the solvent resistance. Further, by bending the glass fiber woven fabric, the flexibility of the portion to which the anti-fray adhesive agent was applied was evaluated. The results are shown in Table 1. (4). Further, as for the obtained anti-fraying adhesive-coated glass fiber woven fabric, a prepreg was prepared, cut into a certain size and stacked, and as a result, almost no difference in height between the end portion and the central portion was observed.

<Examples 2 to 7> Six examples were carried out in the same manner as in Example 1 except that the curing accelerator and the flexibility-imparting agent shown in Table 1 were used in the proportions shown in Table 1. A glass fiber fabric coated with an anti-fraying adhesive agent was obtained, and these physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Examples 1 to 4> As shown in Table 1, a curing accelerator (imidazole) and a reactive flexibility-imparting agent (polyethylene glycol) were used, and at least one of them is the amount of the present invention. The four types of comparative treatment liquids were prepared, which were not included in the range of specific limitation. The obtained treatment liquid was applied to a glass fiber woven fabric in the same manner as in Example 1, dried and cured, and then the physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0023]

[Table 1] The following are clear from Table 1. (A) An example using an anti-fray adhesive in which the curing accelerator is in the range of 2 to 10 parts by weight and the reactive flexibility-imparting agent is in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the bisphenol type epoxy resin. In the case of 1 to 7, the ear fraying strength, the solvent resistance and the flexibility of the coating film were excellent. (B) In the case of Comparative Example 1 in which the amount of the curing accelerator is 1 part by weight and less than the limiting range of the present invention and Comparative Example 2 in which the amount of the curing accelerator is 13 parts by weight and exceeds the limiting range of the present invention, Ear fray strength and solvent resistance were far inferior to Examples 1-7. Further, in the case of Comparative Example 3 in which the amount of the flexibility-imparting agent was 0.5 parts by weight, which was less than the limited range of the present invention, the flexibility of the coating film was poor. In the case of Comparative Example 4 in which the amount of the flexibility-imparting agent is 23 parts by weight and exceeds the limit range of the present invention, the ear fray strength is improved as compared with Comparative Examples 1 and 2, but it is still insufficient and the resistance to abrasion is low. It was also inferior in solvent properties.

[0024]

The anti-raveling adhesive of the present invention has a long pot life at room temperature and a short curing time when heated, and therefore is excellent in handleability and productivity when applied to a glass fiber woven fabric. Since the ears of the glass fiber fabric coated with this anti-ravel agent have been removed, the glass fibers in the ears are not cut off during the production of the prepreg and are not mixed into the prepreg resin varnish, and the anti-ravel agent is applied. The frayed portion has a large fraying strength and excellent solvent resistance to various solvents. Further, since the coated portion has flexibility in the applied portion, it does not crack or break during handling. Even if many glass fiber woven fabrics were stacked as prepregs, there was almost no difference in height, and the cut ends on both sides were also straight.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location D03D 15/12 7199-3B D06C 25/00 A // D06M 23/18 D06M 101: 00

Claims (2)

[Claims] 1. A bisphenol type epoxy resin 10
0 parts by weight, 2 to 10 parts by weight of an imidazole-based and / or tertiary amine-based curing accelerator, and a reactive flexibility-imparting agent 2
~ 20 parts by weight of a glass fiber woven fabric anti-fraying adhesive. 2. The glass according to claim 1, wherein the anti-fraying adhesive agent for glass fiber fabric is applied to a certain width of both ears in an amount of 5% to 10% based on the weight of the glass fiber fabric. Textile fabric.