JP4432508B2 - Method for producing glass cloth having resin adhered to side edge and aqueous composition for obtaining said glass cloth - Google Patents

Description

  The present invention relates to a method for producing a glass cloth in which a resin adheres to a pair of opposing side edge portions, and an aqueous composition for obtaining the glass cloth.

  In recent years, glass cloth manufactured by a plain loom such as an air jet loom capable of achieving high production efficiency has become the mainstream. A glass cloth manufactured by a braided loom inserts a weft thread between a plurality of aligned warps and cuts the weft thread each time it is inserted. It has a part generally called a tufted ear in which the parts are arranged in a tufted shape.

  However, when a glass cloth having such tuft ears is used as an insulating material for a printed wiring board, warp yarns are easily frayed from the tuft ears, causing problems such as winding around a roller during the prepreg manufacturing process. In addition, the resin is excessively impregnated in the tuft ears, so that the thickness of the prepreg is not uniform, and unevenness in the warp direction is likely to occur at the side edge of the prepreg due to the tuft ears.

  Therefore, a method for avoiding the above problem by cutting the side edges of the glass cloth and removing the tufted ears has been conventionally known. Further, the glass cloth before the side edges of the glass cloth are cut. A glass cloth manufacturing method for preventing fraying at the side edge of the glass cloth after cutting has been studied so far by adhering the glass fiber to each other to fix the glass fibers to each other.

  The fixing agent used in such a glass cloth manufacturing method is attached to the glass cloth in a state of a uniform solution or a dispersion liquid such as an emulsion, and forms a resin by a process such as heating or exposure to fix the glass fiber. In the past, compositions using mainly chlorinated organic solvents have been used, but recently, particularly in order to reduce environmental health problems, the fixing component is dissolved or dispersed in water. Many studies have been made on a fixing agent comprising an aqueous composition.

  As a fixing agent comprising an aqueous composition, a composition in which an epoxy resin-based crosslinking agent is combined with an aqueous polyurethane (for example, Patent Document 1), an aqueous polyester, an aqueous polyurethane, and an aqueous melamine resin cross-linkage have been used. A composition (for example, Patent Document 2) combined with an agent, a composition containing a polyamide resin (for example, Patent Document 3), and the like are known.

On the other hand, as an aqueous composition other than the above, an aqueous composition in which an aqueous polyurethane and an oxazoline group-containing compound are combined is known, and there is an example in which this is used as a coating agent composition used as a paint or a surface treatment agent. . For example, Patent Document 4 discloses an aqueous composition in which a water-based polyurethane having a specific structure having a carboxyl group and a cross-linking agent having an oxazoline group are combined for the main purpose of improving the water resistance, alkali resistance and the like of the film. A coating agent composition is disclosed.
JP-A-9-208920 JP 2003-3375 A JP 2001-181982 A JP-A-5-202336

  However, when a glass cloth having a resin adhering to the side edge portion is produced using a fixing agent made of the aqueous composition, there is a problem that the resin bleeds at the side edge portion. Usually, the fixing agent is attached to the side edge of the glass cloth with a constant width, but mainly during the heat treatment, a part of the fixing agent soaks into the glass cloth in the region adjacent to the fixed width region (attachment portion). There is a case where the blur occurs and the blur remains on the side edge portion of the glass cloth after the adhering portion is removed while leaving a part thereof. In the case of organic solvent-based fixing agents that have been used in the past, such bleeding is rare, but when an aqueous composition is used as a fixing agent, bleeding tends to occur.

  Since the glass cloth having a bleed at the side edge portion is used while avoiding a bleed region, the usable area is reduced, and the size and shape of the prepreg may be limited, leading to a decrease in yield. Further, if the side edges of the glass cloth are blurred, the appearance may be impaired and the commercial value of the glass cloth may be reduced.

  The present invention has been made in view of the above circumstances, and provides a method of manufacturing a glass cloth that prevents fraying at the side edge of the glass cloth and also prevents bleeding while using an aqueous composition. Objective.

  The bleeding at the glass cloth side edge is considered to be caused as a result of the sticking agent adhering to the glass cloth having a significantly reduced viscosity during the heat treatment and soaking into the glass cloth in the region adjacent to the adhering part. Therefore, in order to prevent bleeding, for example, by using a highly reactive cross-linking agent or increasing the temperature of the heat treatment to increase the speed of the cross-linking reaction, the fixing agent can be as much as possible during the heat treatment. It is considered effective not to lower the viscosity.

  However, during the heat treatment, even if the crosslinking reaction of the fixing agent starts, the viscosity of the fixing agent does not increase immediately, but after the crosslinking reaction proceeds to some extent, the viscosity starts to increase, that is, until the viscosity increases. It is usually not easy to prevent bleeding even if a highly reactive crosslinking agent is used or the heat treatment temperature is increased, and the reaction of the crosslinking agent Increasing the property also causes a problem that the stability with time of the aqueous composition is impaired. In particular, in the case of a system that requires a relatively long time for drying water, such as an aqueous composition, it has been extremely difficult to find a crosslinking agent and heat treatment conditions that do not cause bleeding.

  However, the present inventors used a water-based composition in which a carboxyl group-containing polyriurethane is combined with an oxazoline group-containing compound that forms a resin by reacting with the polyurethane as a glass cloth fixing agent, and further heated at a specific temperature. Surprisingly, it has been found that the effect of preventing bleeding at the side edge of the glass cloth can be obtained by the treatment, and the present invention has been completed.

  That is, according to the method for producing a glass cloth of the present invention, a carboxyl group-containing polyurethane and an oxazoline group-containing compound that forms a resin by reacting with the polyurethane are dissolved in water at a pair of opposite side edges of the glass cloth. Alternatively, the dispersed aqueous composition is adhered to form an adhering portion, the adhering aqueous composition is heated at 150 ° C. to 230 ° C. to form a resin at the adhering portion, and the resin is formed. And a removing step of removing the adhered portion, leaving a part of the adhered portion, and a method for producing a glass cloth in which a resin adheres to a pair of opposing side edge portions.

  Although the mechanism by which bleeding can be prevented by such a production method is not necessarily clarified, for example, the possibility that the rate of crosslinking reaction between a carboxyl group and an oxazoline group is particularly large in a temperature range of 150 ° C. or higher. There is a possibility that the aqueous composition has gelled at a relatively early stage and has lost its fluidity.

  The present invention also provides an aqueous composition in which a carboxyl group-containing polyurethane and an oxazoline group-containing compound that reacts with the polyurethane to form a resin are dissolved or dispersed in water, and a pair of opposing sides of a glass cloth An aqueous composition for adhering to the edge.

  Furthermore, the present invention is a glass cloth in which a resin formed by a reaction between a carboxyl group-containing polyurethane and an oxazoline group-containing compound is attached to a pair of opposing side edge portions. This glass cloth can be obtained by the above-described method for producing glass cloth using the aqueous composition of the present invention.

  In such a glass cloth of the present invention, fraying at the side edge is small, and the occurrence of bleeding due to the resin is also suppressed.

  According to the method for producing a glass cloth of the present invention, it is possible to prevent bleeding at the side edge of the glass cloth while using the aqueous composition. Further, according to the method for producing a glass cloth of the present invention, the resin formed on the side edge can be prevented from fraying from the side edge in the obtained glass cloth while using an aqueous composition having excellent stability over time. The solvent resistance is excellent, the coloring is small, and the flexibility is not impaired, so that generation of wrinkles can be suppressed.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  The aqueous composition of the present invention is a composition in which a carboxyl group-containing polyurethane and an oxazoline group-containing compound are dissolved in water or dispersed in water in the state of an emulsion, colloidal dispersion, etc. As an agent, it can be used conveniently.

  Such an aqueous composition can be obtained, for example, by separately preparing a liquid in which a carboxyl group-containing polyurethane and an oxazoline group-containing compound are dissolved or dispersed in water, and mixing them uniformly. It is also possible to obtain a solution obtained by dissolving or dispersing either one in water and adding the other to dissolve or disperse.

  Emulsions dispersed in water can be prepared by adding a solution in which components to be dispersed are dissolved in an organic solvent to water while stirring and distilling the organic solvent, or by emulsion polymerization while dispersing the raw material compound in water. Obtainable.

  The carboxyl group-containing polyurethane used in the aqueous composition is a polymer having a urethane bond in the main chain and a carboxyl group at the side chain or terminal. Moreover, the carboxyl group which this polyurethane has may exist as carboxylic acid in an aqueous composition, and may exist as carboxylates, such as a metal salt and ammonium salt.

  The carboxyl group-containing polyurethane is obtained, for example, by a method of reacting a urethane prepolymer having an isocyanate group obtained by polymerizing a polyol and a polyisocyanate and a carboxylic acid compound having an active hydrogen group such as a hydroxyl group or an amino group. be able to.

  The polyol for obtaining the carboxyl group-containing polyurethane may be a compound having two or more hydroxyl groups, and the polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups.

  Examples of the carboxylic acid compound having an active hydrogen group include dimethylolpropionic acid, dimethylolbutanoic acid, glycolic acid, and lactic acid, which are carboxylic acids having a hydroxyl group. Examples thereof include diaminophenylcarboxylic acid, a reaction product of polyamine and acid anhydride, and the like, and these can be used alone or in combination to introduce a carboxyl group into polyurethane.

（式中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４は、それぞれ独立に水素原子または１価の有機基を示す。） The oxazoline group-containing compound used in the aqueous composition of the present invention is a compound having an oxazoline group represented by the following general formula (1) in the chemical structure, and reacts with a carboxyl group-containing polyurethane to form a resin. is there.

(In the formula, R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a monovalent organic group.)

  The aqueous composition in which the carboxy group-containing polyurethane and the oxazoline group-containing compound are combined is stable at room temperature and excellent in stability over time, but when heated, the carboxyl group and the oxazoline group react with each other to form a resin on the adhesion part. Is formed. The glass fibers at the side edges of the glass cloth are fixed to each other by the formed resin, and fraying can be prevented.

  When a compound having two or more oxazoline groups in one molecule is used as the oxazoline group-containing compound, the resin formed by reacting with the carboxyl group-containing polyurethane more strongly fixes the glass fibers to each other, and the glass cloth side It is preferable because fraying from the edge can be reduced.

  As the oxazoline group-containing compound, it is particularly preferable to use a polymer having a plurality of oxazoline groups in the side chain because the flexibility of the obtained glass cloth is increased. A polymer having an oxazoline group in the side chain can be obtained by radical polymerization of an oxazoline group-containing compound having a radical polymerizable functional group such as a vinyl group.

  Examples of the radical polymerizable oxazoline group-containing compound include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2- There are oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and these are used alone or in combination Can be used. Among these, 2-isopropenyl-2-oxazoline is preferable because it can be produced at low cost.

  Furthermore, the above polymer having a plurality of oxazoline groups in the side chain is a radically polymerizable compound such as styrene, methyl methacrylate, t-butyl methacrylate, butyl acrylate, lauryl methacrylate, and cyclohexyl methacrylate, together with a radically polymerizable oxazoline group-containing compound. It is preferable that the monomers are copolymerized alone or in combination.

  In the aqueous composition, the solid content of the carboxyl group-containing polyurethane and the oxazoline group-containing compound is preferably 3% by weight to 20% by weight, and preferably 5% by weight to the total amount of the aqueous composition. More preferably, it is 15% by weight. If the blending amount is less than 3% by weight, fraying at the side edge portion is likely to occur. If the blending amount exceeds 20% by weight, the viscosity of the aqueous composition increases and the impregnation property into the glass cloth is insufficient. In some cases, the attachment process of the invention may be hindered.

  In the aqueous composition, water is used as a solvent or a dispersion medium, but only water may be used. In addition to water, alcohols such as propanol, butanol, methanol, ethanol, propylene glycol monomethyl ether, etc. may be used. Such a hydrophilic solvent may be contained.

  Moreover, you may mix | blend components other than the above, such as surfactant and an antifoamer, with an aqueous composition.

  Using the aqueous composition of the present invention described above as a fixing agent, a glass cloth having a resin adhered to a pair of opposing side edges can be obtained, preferably by the production method described below.

  FIG. 1 is a top view of a glass cloth to which an aqueous composition is attached in an embodiment of a production method according to the present invention. A glass cloth 1 shown in FIG. 1 is composed of a plurality of warps 3 and wefts 5, which are formed so as to intersect each other. In the adhering step, the adhering portion is formed by adhering the water-based composition over the entire length of the side edge portion to a region having a constant width substantially parallel to the warp yarn 3 on a pair of opposing side edge portions of the glass cloth 1. In this case, the side edge portion refers to the outermost end portion where the ends of the wefts of the glass cloth are arranged and a region in the vicinity thereof.

  FIG. 2 is a top view of the glass cloth in which the adhesion portion is formed in this manner. In the glass cloth 1 shown in FIG. 2, the adhering part 10 is formed in the area | region of the fixed width | variety substantially parallel to a warp in a pair of side edge part which the glass cloth 1 opposes.

  The adhering portion 10 may be formed in a region including the endmost portion where the ends of the warp or weft are arranged, or may be formed only in the inner region not including the endmost portion, and the width of the entire glass cloth. Is usually about 1.0 m to 1.3 m, but the width of the adhering portion 10 is preferably 5 mm to 15 mm. If the width of the adhesion part 10 is less than 5 mm, the fraying prevention effect from the side edge part after the removal step may not be sufficient, and if it exceeds 15 mm, the glass cloth area other than the adhesion part becomes narrow.

  Moreover, although the aqueous composition mentioned above is used in an adhesion process, the quantity of resin adhering to the glass cloth after a heating process will be 1 to 10 weight% with respect to the weight of the glass cloth of an adhesion part. It is preferable to attach the aqueous composition in such an amount. Furthermore, when the thickness of the glass cloth is 100 μm to 250 μm, it is more preferable to deposit 2 wt% to 5 wt%, and when the thickness of the glass cloth is less than 100 μm, 4 wt% to 7 wt% is more preferable. If the adhesion amount of the resin after the heating step is less than 1% by weight, the fraying prevention effect may not be sufficient, and if it exceeds 10% by weight, it may cause unevenness in the prepreg.

  As a method for attaching the aqueous composition to the glass cloth, methods such as roll coating, brush coating, dip coating, spray coating, gravure coating, curtain flow coating, and various printing methods can be used. In particular, when using a long glass cloth that is wound in a roll shape, a certain amount of aqueous composition is roll-coated on the area to be adhered while the unwinded glass cloth is advanced in the warp direction. It is preferable that the aqueous composition is continuously adhered because of high production efficiency.

  The glass cloth is made by weaving glass fiber bundles, but other fiber bundles such as carbon fibers and nylon fibers may be partially included in addition to the glass fiber bundles. In particular, those woven by a plain weaving machine such as an air jet loom are liable to fray at the side edge, and are preferably used in the production method of the present invention to prevent fraying. In addition, a glass cloth that has been subjected to deoiling treatment by heat cleaning or the like after weaving and surface-treated with a silane coupling agent or the like can be suitably used.

  As the glass fiber filaments constituting the glass cloth, glass fiber filaments made of E glass, S glass, C glass, D glass, low dielectric glass or the like can be used, but those made of E glass are preferred. Moreover, it is preferable that the fiber diameter of a glass fiber filament is 3 micrometers-13 micrometers.

  The warp and weft constituting the glass cloth are preferably composed of a glass fiber bundle of 5 TEX to 500 TEX (preferably 10 TEX to 200 TEX) in which 50 to 500 (preferably 100 to 400) glass fiber filaments are bundled. . The glass fiber bundle may be substantially untwisted or twisted.

  The glass cloth is preferably woven using such a glass fiber bundle so that the weave density in the warp direction and the weft direction is 30 to 100/25 mm, respectively.

  The thickness of the glass cloth is preferably 15 μm to 250 μm. In particular, in the case of a thin or ultrathin glass cloth having a thickness of 100 μm or less, wrinkles are likely to occur according to the prior art. Therefore, wrinkles are less likely to occur, which is also advantageous in terms of preventing wrinkles over the prior art.

  In the heating step, the water-based composition attached to the glass cloth in the attachment step is heated to remove moisture, and the crosslinking reaction between the polyurethane carboxyl group and the oxazoline group proceeds to form a resin. .

  Here, it is very important to perform heating at 150 to 230 ° C. If it is less than 150 ° C, the effect of preventing bleeding, solvent resistance, and fraying strength are not sufficient, and if it exceeds 230 ° C, the resin may be oxidized and colored, and the adhesion part is sufficiently flexible. Not. Furthermore, in order to further reduce the bleeding, the temperature range is more preferably 180 ° C. to 220 ° C.

  In the heating step, heating may be performed under the condition that the surface temperature of the aqueous composition to be heated or the ambient temperature in the vicinity of the aqueous composition is within the above temperature range. For example, when heating in a heating oven, the ambient temperature in the heating oven may be within the above temperature range.

  As a heating method, an infrared heater such as a short wavelength infrared heater, a medium wavelength infrared heater, a carbon heater, a microwave irradiator, or the like can be used. In order to increase the efficiency of the heat treatment, a carbon heater is used. Is particularly preferred.

  FIG. 3 is a top view of a glass cloth having a resin adhered to a pair of opposing side edge portions. The glass cloth 1 shown in FIG. 3 is a glass cloth obtained by the heating process, in which the adhering portion 10 is removed leaving a part thereof, and an adhering portion 12 having a resin adhering to a pair of opposing side edge portions is formed. It is. In addition, the adhesion part 12 consists of resin after the heating process, ie, the resin in which the water | moisture content was substantially lost and the crosslinked structure was formed.

  The removal of the adhering part can be performed by cutting the glass cloth at the adhering part before the removing process. For cutting the glass cloth, a slitter equipped with a rotary blade, a laser type, a water jet type, etc. Various cutters can be used.

  In the removal process, in order to reduce the restrictions on the shape and size of the cut pattern when used as a prepreg or the like, the adhering portion is such that the pair of opposing side edge portions of the glass cloth after removal are substantially parallel to each other. It is preferable to remove a part of the warp yarn, and it is preferable to remove the warp yarn or the weft yarn, particularly in parallel with the warp yarn.

  In the production method of the present invention, the attachment step, the heating step, and the removal step can be performed separately, but from the viewpoint of production efficiency, the attachment step, the overheating step, and the removal are performed while the glass cloth is being advanced. It is preferable to carry out the steps continuously. Furthermore, a step of performing a silane coupling treatment before the attaching step and a step of obtaining a prepreg by impregnating a glass cloth with a thermosetting resin after the removing step may be performed continuously. it can. According to the manufacturing method of the present invention, the time required for the heating step can be shortened compared to the prior art, and it is also suitable for the continuous process as described above.

  FIG. 4 is a perspective view schematically showing one embodiment of a glass cloth obtained by the production method of the present invention.

  The glass cloth 1 shown in FIG. 4 includes a glass cloth formed by intersecting a plurality of warp yarns 3 and weft yarns 5, and an attachment portion 12 formed substantially parallel to the warp yarn 3 over the entire length of a pair of opposing side edge portions. And.

  In a pair of side edge portions of the glass cloth facing each other, it is preferable that the resin adheres to a region including the end face in order to prevent fraying from the side edge portions. Furthermore, it is preferable that the resin adheres over the entire length of each of the pair of opposing side edge portions, but the side edge portion to which the resin is not attached is partially such that the fraying prevention effect is not substantially lost. May be present. Further, the resin impregnates not only the surface but also the inside of the glass cloth in the adhering portion, but there may be an unimpregnated portion inside so as not to substantially lose the fraying prevention effect.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Evaluation methods)
In this example, the amount of resin adhesion, solvent resistance, fraying strength, flexibility and bleeding were evaluated by the following methods.

[Amount of resin adhesion]
The amount of resin adhered to the glass cloth was measured according to the following procedure.
(1) from glass cloth attachment, and the weight was measured length of the warp direction is cut test piece to be 80～100Cm, and W _1.
(2) The cut specimen is heated for 30 minutes in an electric muffle furnace having a furnace temperature of 625 ° C. ± 10 ° C. to burn the resin.
(3) test specimens were removed from the electric muffle furnace was allowed to stand to cool in a desiccator for 60 minutes, and W ₂ by measuring the weight of the test piece.
(4) The resin adhesion amount is calculated by the following formula.

Resin adhesion amount = {(W ₁ −W ₂ ) / W ₁ } × 100 [%]

[Solvent resistance]
The elution amount from the resin to the solvent was measured according to the following procedure to evaluate the solvent resistance. In addition, the smaller the elution amount, the better the solvent resistance.
(1) from glass cloth attachment, and the weight was measured length of the warp direction is cut test piece to be 80～100Cm, and W _3.
(2) The cut specimen is immersed in dimethylformamide for 1 hour.
(3) After dipping, the test piece is dried for 10 minutes in a hot air drier at a furnace temperature of 50 ° C., and then the weight of the test piece is measured to obtain W ₄ .
(4) The test piece after drying is heated in an electric muffle furnace at a furnace temperature of 625 ° C. ± 10 ° C. for 30 minutes to burn the resin.
(5) After the test piece cooled and left in a dessicator removed from an electric muffle furnace for 60 minutes, and W ₅ by measuring the weight of the test piece.
(6) The elution amount is calculated by the following formula.

Elution amount = {(W ₃ −W ₄ ) / (W ₃ −W ₅ )} × 100 [%]

[Ear fray strength]
Ear fraying strength (fraying strength of warps at the side edge after the removal step) was measured according to the following procedure.
(1) Pull out one warp located at the end of the side edge, and then pull out the second warp from the end so that the length of 1.5 cm remains at the side edge.
(2) The warp having a length of 1.5 cm was pulled in a direction perpendicular to the longitudinal direction of the warp, the maximum load until the pulled warp was pulled out was measured, and the value was taken as the fraying strength.

[Flexibility]
The flexibility of the glass cloth was evaluated according to the following procedure.
(1) From a glass cloth to which a resin having an amount of 10 g / m ² is adhered, a test piece is cut into a size of 15 cm in the warp direction and 2.5 cm in the weft direction.
(2) The cut specimen is fixed on a horizontal table in a state protruding 14 cm from the end of the table in the warp direction. At this time, the protruding portion of the glass cloth is drooped greatly as the flexibility of the glass cloth increases.
(3) The distance [mm] between the tip of the glass cloth that hangs down and the plane including the horizontal portion of the glass cloth is measured, and the magnitude of the distance is used as an index of flexibility.

[Smear]
The bleeding in the glass cloth was evaluated according to the following procedure.
(1) A portion of a glass cloth cut to a size of 10 cm square in the warp direction and the weft direction was immersed in an aqueous composition for 5 seconds in a state where the weft direction was perpendicular to the water surface. Thereafter, the glass cloth was heat-treated under the conditions shown in Table 1.
(2) In the glass cloth after the heat treatment, the width in the warp direction of the bleeding portion (the portion sticking out the region immersed in the aqueous composition and adhering the resin) was measured. The same measurement was performed 5 times, and the obtained value was used as a blur index.

(Preparation of aqueous composition)
[Preparation of aqueous composition 1]
Carboxyl group-containing aqueous polyurethane (Asahi Denka Kogyo Co., Ltd. HUX-522, solid content 30% by weight) 100 parts by weight, oxazoline group-containing compound (Nagase Chemtex Corporation Catalyst # 502, solid content concentration 40% by weight) 1.5 weight Parts of water and 205 parts by weight of water were mixed to prepare an aqueous composition 1 having a solid content of 10% by weight.

  When the aqueous composition 1 was allowed to stand at 60 ° C. for 24 hours, its aging stability was evaluated by confirming its coloration and viscosity change over time, no change in viscosity was observed, and there was little coloration. The temporal stability of the aqueous composition 1 was good.

[Preparation of aqueous composition 2]
Aqueous composition 2 having a solid content of 10% by weight was prepared by mixing 100 parts by weight of a carboxyl group-containing aqueous polyurethane (HUX-522 manufactured by Asahi Denka Kogyo Co., Ltd., solid content: 30% by weight) and 200 parts by weight of water.

  When the aqueous composition 2 was evaluated for stability over time in the same manner as the aqueous composition 1, neither coloration nor viscosity change was observed, and the aqueous composition 2 had good stability over time.

[Preparation of aqueous composition 3]
100 parts by weight of a carboxyl group-containing aqueous polyurethane (HUX-522 manufactured by Asahi Denka Kogyo Co., Ltd., solid content 30% by weight), 1.5 parts by weight of an epoxy group-containing compound (TB-101 manufactured by Sanyo Chemical Co., Ltd., solid content 30% by weight) and 20 parts by weight of water was mixed to prepare an aqueous composition 3 having a solid content of 10% by weight.

  For the aqueous composition 3, the stability over time was evaluated in the same manner as in the case of the aqueous composition 1. As a result, the color was remarkably discolored and gelation was observed. It was a level with practical problems such as difficulty.

Example 1
Using the aqueous composition 1, a glass cloth in which a resin is adhered to a pair of side edges facing each other is prepared by the following procedure, and the obtained glass cloth is subjected to solvent resistance and ear according to the above-described method. Fraying strength was evaluated.

  Moreover, according to the method mentioned above using the aqueous composition 1, it heat-processed at the temperature and time shown in Table 1, and evaluated the softness | flexibility and the blur.

  These evaluation results are shown together in Table 1 together with the evaluation results of Examples 2 to 5 and Comparative Examples 1 to 5.

[Adhesion process]
The aqueous composition 1 was adhered to a glass cloth (IPC standard 7628 type) region having a width of 10 mm at the side edge parallel to the warp with a roller coater to form an adhesion part.

[Heating process]
The adhered aqueous composition 1 was heated in a drying furnace set at 200 ° C. for 20 seconds to obtain a glass cloth (resin adhesion amount: 3.1 wt%) in which a resin was formed on the adhesion part.

  The colored state of the resin on the glass cloth adhering portion was visually confirmed. If almost colorless, “◯” was indicated, and if clear coloring was observed, “X” was indicated. The coloring results of Examples 1 to 5 and Comparative Examples 1 to 5 are summarized in Table 1.

[Removal process]
Cut the glass cloth with a slitter parallel to the warp direction along the approximate center of the attached part after the heating process, remove the part of the attached part, and attach the glass cloth with the resin attached to a pair of opposing side edges. Obtained.

(Examples 2-5, Comparative Examples 1-3)
A glass cloth was prepared in the same manner as in Example 1 except that the heat treatment was performed at the temperature and time shown in Table 1, and solvent resistance, fraying strength, coloring, and bleeding were evaluated.

(Comparative Example 4)
A glass cloth was prepared in the same manner as in Example 1 except that the aqueous composition 2 was used in place of the aqueous composition 1, and the solvent resistance, flexibility, ear fraying strength, coloring, and bleeding were evaluated. .

(Comparative Example 5)
In place of the aqueous composition 1, except for using the aqueous composition 3, the cutting of the glass cloth ear part and the evaluation of solvent resistance, flexibility, ear fraying strength, coloring, and blurring were performed in the same manner as in Example 1. went. By using the epoxy group-containing compound, the bleeding was relatively good, but the flexibility was inferior. Accordingly, the aqueous composition 3 is considered to be disadvantageous in terms of preventing wrinkles as compared with the aqueous composition 1 when used in a thin glass cloth.

It is a top view of the glass cloth which adheres an aqueous composition in one Embodiment of the manufacturing method concerning this invention. It is a top view of the glass cloth in which the adhesion part was formed in one Embodiment of the manufacturing method concerning this invention. It is a top view of the glass cloth which resin adhered to a pair of side edge part which opposes in one Embodiment of the manufacturing method concerning this invention. It is a perspective view which shows typically one Embodiment of the glass cloth obtained by the manufacturing method of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Glass cloth, 3 ... Warp, 5 ... Weft, 10 ... Adhering part (before removal process), 12 ... Adhering part (after removal process)

Claims (2)

On a pair of opposing side edges of the glass cloth,
An adhesion step in which a carboxyl group-containing polyurethane and an oxazoline group-containing compound that reacts with the polyurethane to form a resin are attached to a water-based composition dissolved or dispersed in water to form an attachment part;
Heating the adhered aqueous composition at 150 ° C. to 230 ° C. to form the resin at the adhered portion;
A removing step of removing the adhering portion where the resin is formed, leaving a part of the adhering portion;
The manufacturing method of the glass cloth with which resin adhered to a pair of side edge part which opposes.   A glass cloth in which a resin formed by a reaction between a carboxyl group-containing polyurethane and an oxazoline group-containing compound is attached to a pair of opposing side edges.

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