JPS6385158A - Glass cloth - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a glass cloth whose edges are fixed with a polyester copolymer to prevent fraying.

This invention relates to glass cloth used for printed circuit boards.

(Conventional technology) Glass cloth was traditionally woven using shuttle looms, but with the development of high-speed piece looms such as air jet looms, its use rapidly came to be used due to its high quality. . In particular, glass cloth used for electrical insulation purposes is required to be as clean as possible, and glass cloth woven with an air jet loom is useful in this sense. However, in the tuft selvage of glass cloth woven with a fragmentary loom, the weft threads are cut somewhat longer than 11 of the cloth.

When a glass cloth woven using a fragmentary loom is impregnated with a resin fabric, there is a problem in that the fabric adheres too much to the tassel edges.

Furthermore, the tufted edges of glass cloth woven using a fragmentary loom tend to bend easily, resulting in problems such as loss of smoothness or snagging, resulting in poor workability. For example, when glass cloth is used as a material for printed circuit boards, the glass cloth is impregnated with an engineered boxy resin varnish, dried to harden the resin, and the resulting prepreg is cut into a certain shape. It is overlapped later.

There was a problem in that workability was poor in such a step of overlapping.

Therefore, it has been proposed to shorten the length of the tassel selvedges when weaving with a fragmentary loom. However, in such a case, there was a problem that the warp threads were easily frayed.

Nine different methods have been proposed to prevent such fraying. For example, Japanese Patent Publication No. 50-15908 discloses a method of cutting the glass fibers of the tufted edges or the base of the cloth while melting and adhering them using a laser beam. However, the melt adhesive strength of glass fibers obtained by such a method is weak, and in addition, minute glass balls are generated during cutting, and these glass balls fall into the varnish during the resin varnish impregnation process. Since the fallen glass bulbs adhere to the surface of the glass cloth during the resin varnish impregnation process, there is a problem in that the surface smoothness of the glass cloth is impaired.

Furthermore, Japanese Patent Application Laid-Open No. 52-34094 discloses a method of applying an adhesive to the tuft and cut portions to prevent fraying. As such an adhesive.

Conventionally, ethylene-vinyl acetate copolymers, copolymers mainly composed of polyamide, thermosetting resins such as epoxy resins and phenol resins, and thermoplastic resins such as nylon, polyethylene terephthalate, polybutylene terephthalate, and polyphenylene ether are known. Met. however,
Such adhesives have poor solvent resistance to varnish solvents. Adhesion to glass cloth and fraying prevention effect are poor.

Alternatively, there is a problem in that the curing speed of the impregnated resin is reduced, and an improvement has been desired. Specifically, the solvent resistance of varnish to solvents refers to acetone,
Methyl ethyl ketone, methyl cellosolve, methanol,
It must not dissolve in ethanol, dimethylformamide, toluene, hexane, etc.

In order to solve this problem with adhesives,
No. 143 discloses that aromatic dibasic acid (however, 90 mol% or more of the aromatic dibasic acid is terephthalic acid) residue is
~50 mol% and 10 to 50 mol% of aliphatic dicarboxylic acid residues with a methylene group number of 10 to 50 mol%, and 40 to 100 diethylene glycol residues as a glycol component.
Copolymerized polyesters having 60 to θ mol % of alkylene glycol residues having 6 or less carbon atoms have been proposed. In addition, JP-A No. 54-96197 discloses 36 to 84 mol% of terephthalic acid as a dibasic acid component;
Isophthalic acid 14-1 mol% and aliphatic dicarboxylic acid 5
A copolymerized polyester consisting of 0 to 15 mol % and 80 to 20 mol % of ethylene glycol and 20 to 80 mol % of 1,4-butanediol as glycol components has been proposed.

(Problems to be Solved by the Invention) However, although such polyester copolymers have relatively excellent solvent resistance, they are still unsatisfactory in terms of adhesion to glass cloth and fraying prevention effect. .

Therefore, there is a problem in that glass cloth that has been sealed using the above-mentioned anti-fray agent still easily frays.

SUMMARY OF THE INVENTION An object of the present invention is to provide a glass cloth with ear clips that has improved fraying.

Another object of the present invention is to provide a glass cloth with ear closures that does not fray during the varnish impregnation process.

(Means for Solving the Problems) As a result of intensive studies to solve these problems, the inventors of the present invention have found that the purpose can be achieved by using a specific polyester copolymer to prevent fraying. They discovered this and arrived at the present invention.

That is, 1 the present invention consists of a residue of at least one compound selected from the group consisting of a hydroxy acid and a lactone, a terephthalic acid residue and an aliphatic glycol residue; The ratio is substantially equimolar, and the molar ratio of the residue of at least one compound selected from the group consisting of hydroxy acids and lactones to the terephthalic acid residue is 1:4 to 4:1, The gist of the glass cloth is that the ears are fixed and prevented from fraying by a polyester copolymer having a reduced viscosity of 0.5 to 0.9.

The present invention will be explained in detail below.

The polyester copolymer in the present invention is a polyester copolymer consisting of a residue of at least one compound selected from the group consisting of hydroxy acids and lactones, a terephthalic acid residue, and an aliphatic glycol residue.

The hydroxy acids used in the present invention include:

Parahydroxybenzoic acid, metahydroxybenzoic acid, orthohydroxybenzoic acid, where one or more hydrogen atoms in the aromatic ring are an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, or a nitro group. Ortho, meta, parahydroxybenzoic acid substituted with at least - and having 7 to 1 carbon atoms.

2 carbon atoms such as phenylene hydroxy acid, glycolic acid, etc.
-10 aliphatic hydroxy acids, C8-IO aralkylene hydroxy acids, and the like.

The lactones used in the present invention include not only aliphatic lactones having 3 to 10 carbon atoms such as caprolactone and valerolactone, but also aliphatic lactones in which at least one hydrogen atom is an alkyl group, an alkoxyl group, a phenyl group, an aralkyl group, a nitro group, and a halogen atom. Examples include aliphatic lactones having 3 to 10 carbon atoms substituted with at least one of the following.

Terephthalic acid used in the present invention includes:

It may also be terephthalic acid in which one or more hydrogen atoms in the aromatic ring are substituted with at least one of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom, and a nitro group.

Glycols used in the present invention include ethylene glycol and 1,2-propanediol.

C2-C20 alkylene glycols such as 1,4-butanediol and 1,6-hexanediol.

1.4 Alicyclic glycols having 5 to 20 carbon atoms such as cyclohexanediol, and 4 to 20 carbon atoms such as diethylene glycol
20 alkylene ether glycol, carbon number 8-20
Not only araalkylene glycols and ethylene oxide adducts of bisphenol A, but also at least one hydrogen atom of the above glycol is an alkyl group having 1 to 4 carbon atoms,
Examples include glycols substituted with at least one of an alkoxy group having 1 to 4 carbon atoms, a halogen atom, and a nitro group.

The ratio of terephthalic acid residues and aliphatic glycol residues constituting the polyester copolymer of the present invention is about 1:1 with a 9 molar ratio, and at least one compound selected from the group consisting of hydroxy acids and lactones. The ratio of the residue and the terephthalic acid residue is 9 molar ratio of 1:4 to 4:1. Preferably the ratio is 1:3 to 2:1.

When a polyester copolymer in which the ratio of residues of at least one compound selected from the group consisting of hydroxy acids and lactones and terephthalic acid residues is outside this range is used as an agent for preventing fraying of glass cloth, It is difficult to obtain ear-stopped glass cloth with improved fraying.

A part of the terephthalic acid constituting the polyester copolymer of the present invention may be replaced with isophthalic acid, alicyclic dicarboxylic acid, or the like.

In addition, as the polyester copolymer in the present invention,
A dye/pigment 5 polymerization catalyst, a crosslinking agent, etc. may be blended.

The reduced viscosity of the polyester copolymer in the present invention is as follows:
This is a value measured at 30° C. by dissolving 0.1 g of polyester copolymer in water. )0.5-0.9, preferably 0.6-0. It is 8.

The softening point of the polyester copolymer in the present invention is preferably higher than the drying temperature of the varnish, and is preferably at least 100°C, particularly preferably 150°C or higher.

In the present invention, as a glass cloth to which a polyester copolymer is applied as an anti-fray agent.

Examples include glass cloth as described below.

The glass component of the glass fibers constituting the glass cloth may be of any kind, for example.

E-glass, C-glass, S-glass, etc. are preferred, and in particular, as the glass passed through a glass cloth used for printed circuit boards, alkali-free E-glass is preferred.

Further, as for the fiber diameter of the glass fibers constituting the glass cloth, any fiber diameter can be used as long as the glass cloth can be woven, but it is preferably in the range of several microns to several tens of microns.

The glass cloth used in the present invention is obtained by subjecting a glass yarn obtained by combining a plurality of such glass fibers to a warping process and a sizing process, and then weaving the yarn.

The weave structure of the glass cloth used in the present invention is 9
For example, any material other than plain weave, twill weave, satin weave, triaxial weave, etc. may be used.

The number of warp and weft threads per unit length, thickness, and weight per unit area of the glass cloth used in the present invention are R-3414 of the 2nd Wood Industry Standard and American Military Standard (M
It is preferable to use one that corresponds to the IL standard (IL standard), but it is not limited thereto.

The thickness of the glass cloth that meets these standards is about 20 to about 300 microns, and the weight is about 20 to about 350 g/m2.

In addition, the glass cloth used in the present invention includes not only glass cloth that does not meet these standards, but also glass cloth that does not meet these standards.
Fabrics made of glass fibers and fibers other than glass fibers 2 For example, cloths obtained by mixing glass fibers and carbon fibers, mixing fibers with glass fibers and organic fibers, mixing fibers with glass fibers and ceramic fibers, etc. There may be.

The glass cloth used in the present invention includes glass cloth (hereinafter referred to as greige) on which a sizing agent necessary for weaving has been attached, and glass cloth (hereinafter referred to as greige) on which the sizing agent has been removed by wet or dry processing. It may be any glass cloth, such as glass cloth (hereinafter referred to as "cleaned cloth"), gray cloth or glass cloth whose surface is treated with an organic silane compound (hereinafter referred to as "silane treated cloth").

A glass cloth whose edges are fixed and prevented from fraying by the polyester copolymer of the present invention can be obtained by applying the polyester copolymer of the present invention to the above-mentioned glass cloth. 3 For example, a method of applying as a hot melt adhesive,
A method of applying by dissolving in a solvent such as chloroform or methylene chloride.

Conventionally known methods such as applying as an aqueous emulsion and hot pressing a pre-prepared tape-like film can be used.

In either method, it is desirable to apply the polyester copolymer so that it sufficiently penetrates between the filaments of the glass cloth.

The selvedge portion fixed by the polyester copolymer in the present invention may be either a tufted selvage portion of glass cloth woven with a piece loom or a cut portion of cut glass cloth.

The time to cut the glass cloth may be before fixing the glass cloth with the polyester copolymer,
This may be done after applying the polyester copolymer.

Since the polyester copolymer of the present invention has excellent adhesion to glass cloth, it can be used as an agent to prevent fraying of glass cloth.

The fraying prevention effect can be obtained with a relatively small number of stars.

The amount to be applied depends on whether the glass cloth can be rolled into a uniform roll when it is rolled up.
Alternatively, it is preferable to apply the edge height such that the thickness of the laminate obtained by stacking the cut glass cloths does not become uneven.

The fixed and fray-prevented state of the glass cloth of the present invention is a state in which the glass fibers do not substantially fray and fall off.

The fraying prevention strength of the glass fibers in such a fixed state was evaluated by the following method.

Measurement method for anti-tangling strength: Glass cloth woven using an air jet loom (44 warps/25 mm, 33 wefts/25 m)
m0 plain weave 9 weight 210g/m2. thickness 0.18mm)
A methylene chloride solution containing a polyester copolymer with a concentration of 5% by weight was applied to the ground yarn section 5 mm inside from the tassel edge at a rate of 0.14 cc per 100 mm of glass cloth in the direction of the warp so that the width was 8 mm. Apply to impregnate the polyester copolymer solution. After impregnating the polyester copolymer, the solvent is removed by blowing hot air at 180° C. for 45 seconds. After cooling, a 50 mm x 50 piece was cut between the warp threads in the center of the area where the polyester copolymer was applied.
Cut with scissors to the size of mm. Set this cut sample so that the direction of the warp is perpendicular to the direction of the tensile force,
A hook-shaped hook is hung on one of the warp yarns at the end, and the hook is moved at a speed of 1.0 mm/min.

The tensile force required to peel off the warp threads is defined as the fraying prevention strength.

In addition, in order to determine the anti-fray strength under wet conditions in the examples, the above sample obtained by cutting the warp yarns in the center of the area to which the polyester copolymer was applied was placed in dimethylformamide at room temperature. After being immersed in water for 1 minute, it was measured using the method described above.

Further, the solvent resistance of the polyester copolymer and the height of the edge of the glass cloth in the Examples and Comparative Examples described below were each measured as follows.

Method for Measuring Solvent Resistance The same glass cloth used to measure the anti-tangle strength was subsequently immersed in a 5% by weight methylene chloride solution of the polyester copolymer.

The glass cloth is cured by blowing hot air at 180° C. for 60 seconds and then cooled to obtain a glass cloth coated with a polyester copolymer. This glass cloth is immersed in dimethylformamide, xylene, methyl cellosolve and methyl ethyl ketone at 65°C for 1 hour. After soaking and drying, the weight of the glass cloth /! '11. The weight loss rate before and after immersion is used as a measure of solvent resistance.

Regarding acetone, the weight loss rate of the glass cloth after Soxhlet extraction at 65° C. for 1 hour is measured.

Measuring the height of the edges of glass cloth After applying the polyester copolymer to glass cloth, dry it, and measure the thickness of the glass cloth in the coated and uncoated areas using a high-precision thickness gauge (manufactured by Tokyo Process Services). Measure using a high-precision thickness measuring machine, model MG-4).

(Example) The present invention will be explained below by way of examples.

Example 1 Methyl rosehydroquine benzoate, ε-caprolactone,
Terephthalic acid and 1,4-butanediol are polymerized using zinc acetate as a catalyst to form parahydroxybenzoic acid residues versus ε-caprolactone residues versus terephthalic acid residues pairing with 1,4-
The molar ratio of butanediol residues is 10:30:60
vs. 6o.

A polyester copolymer having a reduced viscosity of 0.762 was obtained. A 5% by weight methylene chloride solution of this polyester copolymer was prepared, and the anti-fraying strength, solvent resistance, and height of the edge of the glass cloth were measured by the methods described above. The results are shown in Table 1.

Comparative Example 1 Terephthalic acid, adipic acid, isophthalic acid and 1.4-
When using butanediol, the molar ratio of terephthalic acid residues to adipic acid residues to isophthalic acid residues to 1,4-butanediol residues was 60:30:10:100, and the reduced viscosity was 0.772. A polyester copolymer was obtained. A 5% by weight methylene chloride solution of this polyester copolymer was prepared, and the anti-fade strength was measured in the same manner as in Example 1.

The solvent resistance and the edge height of the glass cloth were measured.

The results are shown in Table 1.

As is clear from Table 1, the glass cloth covered with the polyester copolymer according to the present invention has an excellent anti-fraying effect.

Examples 2 to 4 Table 1 Methyl parahydroxybenzoate (hereinafter abbreviated as POB), ε-caprolactone (hereinafter abbreviated as CL),
Polyester copolymers were produced using terephthalic acid and various glycols shown in Table 2. The composition ratio and reduced viscosity of each component in the obtained polyester copolymer are 1
As shown in Table 2.

A 5% by weight methylene chloride solution of these polyester copolymers was prepared, and in the same manner as in Example 1, the anti-fade strength, solvent resistance, and edge height of glass cloth were measured.

The results are shown in Table 2.

Comparative Examples 2-4 Nine different polyesters were produced in the same manner as in Examples 2-4, except that isophthalic acid was used instead of POB and aliphatic dicarboxylic acid was used instead of CL. The types of glycols constituting these polyesters, the constituent proportions of each component, and the reduced viscosity are as shown in Table 1.

A 5% by weight methylene chloride solution of these polyester copolymers was prepared, and in the same manner as in Example 1, the anti-fade strength, solvent resistance, and edge height of glass cloth were measured.

The results are shown in Table 2.

Note that the abbreviation TPA in Table 1 is terephthal 13.
IpA is isophthal'qJ, ADA is adipic acid, BD
is 1,4-butanediol, MEK is methyl ethyl ketone, and MSS is methyl cellosolve.

DMF stands for dimethylformamide.

As is clear from Table 2, the glass cloth coated with the polyester copolymer of the present invention has an excellent anti-fraying effect.

Table 2 (Effects of the Invention) The glass cloth of the present invention not only has glass fibers that are less likely to fray compared to glass cloth that has been prevented from fraying using a conventionally known anti-fray agent, but also has the problem of high selvage. It is a glass cloth that has been removed.

Furthermore, the glass cloth of the present invention is a glass cloth suitable for impregnation with resin varnish, and particularly suitable for use in printed circuit boards.

Claims (1)

[Claims] (1) Consists of a residue of at least one compound selected from the group consisting of hydroxy acids and lactones, a terephthalic acid residue, and an aliphatic glycol residue, and the ratio of the terephthalic acid residue to the aliphatic glycol residue is substantially The molar ratio of the residue of at least one compound selected from the group consisting of hydroxy acids and lactones to the terephthalic acid residue is 1:4 to 4:1, and the reduced viscosity is 0.5
A glass cloth characterized in that the ears are fixed and prevented from fraying by a polyester copolymer having a molecular weight of 0.9.