Silane-treated quartz glass cloth

Abstract

To provide a silane-treated quartz glass fiber excellent in a dielectric tangent in a high frequency wave zone, and a strength.SOLUTION: A silane-treated quartz glass fiber is a surface-treated product of a quartz glass fiber having a SiO2 content of 95 mass% or more by a (meth)acrylamide group-containing organosilicon compound represented by formula (1) where an organosilicon compound represented by formula (1) is dissolved in water, and the content of a di (meth)acrylamide group-containing organosilicon compound represented by formula (2) is less than 1 pts.mass to 100 pts.mass of the organosilicon compound of formula (1).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a silane-treated quartz glass fiber, and more particularly to a silane-treated quartz glass fiber that is excellent in dielectric tangent and strength in the high frequency band. [Background technology]

[0002] Currently, with the increasing performance and high-speed communication of information terminals such as smartphones, the printed wiring boards used are becoming increasingly denser and thinner, while also exhibiting lower dielectric constant and lower dielectric loss tangent. Glass fiber is used as an insulating material for these printed wiring boards. Among glass fibers, glass cloth in particular is widely used in laminates made by laminating prepregs obtained by impregnating glass fibers with thermosetting resins such as epoxy resins (hereinafter referred to as "matrix resins") and then curing them under heat and pressure.

[0003] It is known that the signal transmission loss in a substrate is improved as the dielectric constant (ε) and dielectric dissipation factor (tanδ) of the material decrease, as indicated by the Edward A. Wolff equation: transmission loss ∝√ε×tanδ. In particular, it is known from the above equation that the dielectric dissipation factor contributes greatly to transmission loss. Therefore, a low dielectric dissipation factor is required for glass cloth, and Patent Documents 1 to 4 propose glass cloths with improved dielectric properties, such as D glass, NE glass, L glass, and quartz glass.

[0004] However, even these low-dielectric-property glass cloths with low dielectric constants and low dielectric dissipation factors still need to be improved in order to achieve sufficient transmission speed performance for future 5G and 6G communication applications. 6G in particular will use radio waves in a higher frequency range for communication, so low-dielectric-property glass cloths with low dielectric constants and low dielectric dissipation factors will be required even at 10 GHz and 40 GHz.

[0005] In addition, demand for substrates for future 5G and 6G communication applications is increasing more than ever, and there is a demand to increase the speed of substrate production lines in order to improve productivity. However, the strength of the glass cloth used as the substrate raw material is low, so the process of applying resin to the glass cloth is the rate-limiting factor in substrate production. In particular, quartz glass cloth has a high SiO2 content and a dielectric loss tangent superior to multi-component glass, but it is hard and brittle, resulting in low strength. In view of the above, there is a demand for glass cloth, particularly quartz glass cloth, to have a further reduced dielectric tangent and increased strength.

[0006] Generally, the strength of glass fiber can be increased by subjecting the SiOH groups on the surface to silane coupling treatment. During this process, the SiOH groups on the surface react with the silane coupling agent, but the silane coupling agent also contains a fair amount of polar groups. As a result, the dielectric loss tangent of the glass fiber after silane treatment remains unchanged or even increases compared to before treatment. In particular, since the dielectric loss tangent of quartz glass fiber is very small, the negative impact of the silane coupling agent itself on the dielectric loss tangent is very large. However, no silane coupling agent has been developed to date that can increase the strength of quartz glass fibers without adversely affecting their dielectric loss tangent. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 5-170483 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-263569 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-19150 [Patent Document 4] Japanese Patent Application Laid-Open No. 2006-282401 Summary of the Invention [Problem to be solved by the invention]

[0008] To prevent fluffing and thread breakage due to mechanical abrasion during winding and weaving, glass fibers, particularly glass cloth, are coated with a sizing agent during spinning and warping of the glass fiber bundles, and the sizing agent is completely removed by a thermal decomposition treatment, or so-called heat cleaning treatment, before silane treatment. The desized glass cloth obtained in this process determines the physical properties of the glass cloth itself. Therefore, there is a need for a silane coupling agent that can increase the strength of this desized glass cloth without deteriorating its dielectric loss tangent.

[0009] The present invention has been made in view of the above problems, and has as its object to provide a silane-treated quartz glass fiber that is excellent in dielectric tangent and strength in the high frequency band. [Means for solving the problem]

[0010] As a result of extensive research into solving the above problems, the present inventors discovered that by surface treating a quartz glass fiber with a specific organosilicon compound containing a methacrylamide group, the low dielectric tangent of the quartz glass fiber can be further reduced and its strength can be increased, leading to the creation of the present invention.

[0011] That is, the present invention is 1. A quartz glass fiber having an SiO2 content of 95% by mass or more, which is surface-treated with a methacrylamide group-containing organosilicon compound represented by the following formula (1): a silane-treated quartz glass fiber that has been surface-treated with a silane treatment solution in which a methacrylamide group-containing organosilicon compound represented by the following formula (1) is dissolved in water, and the content of a dimethacrylamide group-containing organosilicon compound represented by the following formula (2) is less than 1 part by mass per 100 parts by mass of the methacrylamide group-containing organosilicon compound represented by the following formula (1); [ka] (In the formula, R 1each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, Me represents a methyl group, m1 and m2 represent integers of 1 to 3, and n1 and n2 represent integers of 1 to 12. 2. A silane-treated quartz glass cloth containing the silane-treated quartz glass fiber according to 1. 3. The silane-treated quartz glass cloth according to 2, wherein the methacrylamide group-containing organosilicon compound is adhered in an amount of 0.01 to 0.5 mass % based on the quartz glass cloth. 4. The silane-treated quartz glass cloth according to 2 or 3, wherein the dielectric loss tangent at 10 GHz is less than 1 times that before the silane treatment. 5. The silane-treated quartz glass cloth according to 2 or 3, wherein the dielectric loss tangent at 40 GHz is less than 1 times that before the silane treatment. 6. The silane-treated quartz glass cloth according to 2 or 3, having a tensile strength of at least 1.3 times that before silane treatment. 7. A prepreg comprising the silane-treated quartz glass cloth according to 2 or 3 and a matrix resin impregnated into the silane-treated quartz glass cloth. 8. A printed wiring board containing the prepreg according to 7. to provide. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a silane-treated quartz glass fiber that has a further reduced dielectric loss tangent in the high frequency band and excellent strength. Quartz glass cloth containing this silane-treated quartz glass fiber not only stably reduces the transmission loss of substrates for 5G and 6G communication applications in the high frequency band, but also enables the line speed of substrate production to be increased more than ever before, thereby meeting the demand for substrates for 5G and 6G communication applications. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below. [1] Silane-treated quartz glass fiber The silane-treated quartz glass fiber of the present invention is a quartz glass fiber having an SiO2 content of 95% by mass or more, which has been surface-treated with a specified silane treatment solution containing a specified methacrylamide group-containing organosilicon compound. In the present invention, the "silane coupling agent" is included in the "organosilicon compound."

[0014] (1) Quartz glass fiber (1-1) Glass composition The quartz glass fiber used in the present invention preferably has an SiO2 composition of 95% by mass or more, and from the viewpoint of electrical properties such as dielectric loss tangent and physical properties such as thermal expansion, a Q-glass content of 99.9% by mass or more is more preferable. An SiO2 composition of less than 95% by mass is unsuitable because the influence of multiple components becomes too great and adversely affects the dielectric loss tangent and dielectric constant. The quartz glass may be either synthetic quartz glass or fused quartz glass. Components other than SiO2 include Al2O3, CaO, MgO, BO3, Na2O, etc.

[0015] (1-2) Fiber type In the present invention, the term "quartz glass fiber" includes quartz glass filaments, quartz glass strands, chopped quartz glass strands, and quartz glass yarns.

[0016] (1-2-1) Quartz glass filament The quartz glass filaments constitute the quartz glass yarn and are thin, thread-like single fibers obtained by stretching a quartz glass ingot. The method for producing the quartz glass filament is not particularly limited, and any conventionally known production method can be used. For example, a quartz glass ingot with a diameter of 50 to 500 mm is melted at 1700 to 2300°C, and the resulting filament is wound up to obtain a quartz fiber with a diameter of 200±100 μm. If the melting temperature is within this range, stable drawing is possible.

[0017] Because quartz yarn has very low strength, it is preferable to coat it with a coating agent before winding it. The coating agent is preferably an acrylate resin that is UV-curable and has excellent curing properties. The thickness of the coating film is not particularly limited, but a thickness of 5 μm or more is preferable, for example, because it provides sufficient reinforcement. In order to increase productivity, the quartz glass ingot can be cooled between melting and coating. The cooling method is not particularly limited, but examples include water cooling and air cooling, and it is more effective to use both methods.

[0018] The quartz filament can be obtained by re-stretching the quartz yarn, but the method is not particularly limited. For example, it can be obtained by re-stretching it to a diameter of 2 to 15 μm at 1700 to 2300°C in a mixed flame of oxygen and hydrogen.

[0019] (1-2-2) Quartz glass strand The quartz glass strand is a bundle of quartz glass filaments. The number of glass filaments constituting the quartz strand is not particularly limited as long as it is plural; for example, 20 to 400 quartz filaments can be bundled together to produce a quartz strand. In this case, it is preferable to use a sizing agent to bundle the strands. The sizing agent is primarily made of starch, and softeners and lubricants can be blended to impart functionality. The sizing agent composition is generally called a sizing agent.

[0020] (1-2-3) Quartz glass chopped strands The chopped silica glass strands are obtained by cutting silica glass strands. The cutting method is not particularly limited, and for example, a method of cutting to a predetermined length using a conventionally known cutting device can be adopted.

[0021] (1-2-4) Quartz glass yarn The quartz glass yarn is made by twisting quartz glass strands. The silica glass yarn can be obtained by twisting the strand prepared above. The twisting frequency is not particularly limited, but is preferably 0.1 to 5.0 times per 25 mm, for example.

[0022] (2) Silane treatment solution The silane treatment solution (hereinafter sometimes referred to as treatment solution) used in the present invention is an aqueous solution containing a methacrylamide group-containing organosilicon compound represented by the following formula (1) (hereinafter referred to as compound (1)), but substantially free of a dimethacrylamide group-containing organosilicon compound represented by the following formula (2) (hereinafter referred to as compound (2)). In the present invention, "substantially free" means that the content of compound (2) is less than 1 part by mass per 100 parts by mass of compound (1), preferably less than 0.5 parts by mass, and more preferably 0 parts by mass.

[0023] [ka]

[0024] In the formula, R 1 each independently represents an alkyl group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 6 carbon atoms, or an aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, and more preferably 6 to 8 carbon atoms; Me represents a methyl group; m1 and m2 represent integers of 1 to 3; and n1 and n2 represent integers of 1 to 12.

[0025] R 1 The alkyl group having 1 to 10 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl, α-naphthyl, and β-naphthyl groups. Among these, R 1 As the alkyl group, an alkyl group having 1 to 3 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is even more preferable.

[0026] m1 and m2 represent integers of 1 to 3, preferably 2 or 3, and n1 and n2 represent integers of 1 to 12, preferably 1 to 8, more preferably 1 to 4, and even more preferably 3, from the viewpoint of raw material procurement.

[0027] Therefore, compound (1) is R 1 is preferably a methyl group or an ethyl group, and n1 is preferably 3; 1 is a methyl group and n1 is 3. Compound (2) is particularly preferably a compound in which R 1 is preferably a methyl group or an ethyl group, and n2 is preferably 3; 1 is a methyl group and n2 is 3 is particularly preferred.

[0028] Specific examples of compound (1) include methacrylamide methyltrimethoxysilane, methacrylamide methyldimethoxysilane, methacrylamide methyltriethoxysilane, methacrylamide methyldiethoxysilane, 3-methacrylamidopropyltrimethoxysilane, 3-methacrylamidopropylmethyldimethoxysilane, 3-methacrylamidopropyltriethoxysilane, 3-methacrylamidopropylmethyldiethoxysilane, 4-methacrylamidobutyltrimethoxysilane, 4-methacrylamidobutylmethyldimethoxysilane, and 4-methacrylamidobutyl. Examples of the silane include, but are not limited to, 12-methacrylamidododecyltriethoxysilane, 4-methacrylamidobutylmethyldiethoxysilane, 8-methacrylamidooctyltrimethoxysilane, 8-methacrylamidooctylmethyldimethoxysilane, 8-methacrylamidooctyltriethoxysilane, 8-methacrylamidooctylmethyldiethoxysilane, 12-methacrylamidododecyltrimethoxysilane, 12-methacrylamidododecylmethyldimethoxysilane, 12-methacrylamidododecyltriethoxysilane, and 12-methacrylamidododecylmethyldiethoxysilane. These may be used alone or in combination of two or more. Among these, compounds represented by the following formulae are preferred, and from the viewpoints of production and aqueous solution preparation, compounds (1-1) and (1-3) are particularly preferred: In the following formulae, Me represents a methyl group, and Et represents an ethyl group.

[0029] [ka]

[0030] The method for producing compound (1) is not particularly limited, and conventionally known production methods can be used. For example, according to the method described in Japanese Patent No. 3561501, compound (1) can be obtained by reacting a methacrylic acid ester such as methyl methacrylate with an aminoalkylalkoxysilane such as 3-aminopropyltrimethoxysilane in the presence of a polymerization inhibitor and an amidation catalyst at a temperature of about 100 to 200°C. The obtained compound (1) is preferably purified in a subsequent step by vacuum distillation or the like.

[0031] Known amino-group-containing silanes, such as 3-aminopropyltrimethoxysilane, are highly stable when dispersed in aqueous solutions, but they only increase the strength of silica glass fibers when applied to them, and the dielectric loss tangent of the silica glass fibers deteriorates due to the influence of the terminal polar primary amine group. Known methacryl-group-containing silanes, such as 3-methacryloxypropyltrimethoxysilane, are highly stable when applied to silica glass fibers, but they also decrease the dielectric loss tangent of the silica glass fibers due to the influence of the terminal polar carbonyl group. Furthermore, their stability when dispersed in aqueous solutions is inferior to that of amino-group-containing silanes.

[0032] In contrast, the amino group of compound (1) used in the present invention is a secondary amine, which has a lower polarity than primary amines. When compound (1) is applied to quartz glass fiber, the SiOH groups on the surface of the quartz glass fiber, the secondary amine, and the carbonyl group form a stable cyclic structure, canceling out each other's dipoles, which is thought to reduce the dielectric loss tangent of the quartz glass fiber. Furthermore, the inclusion of a methacryl group results in a large increase in strength when applied to quartz glass fiber, and the inclusion of an amino group provides excellent stability when dispersed in an aqueous solution. As described above, compound (1) can further reduce the dielectric loss tangent of quartz glass fiber and increase its strength.

[0033] Japanese Patent Laid-Open Publication No. 5-25219 reports that laminates made of glass fibers treated with a silane coupling agent containing a similar methacrylamide group exhibit excellent heat resistance and other properties. However, the silane coupling agent in question uses a mixture of a compound obtained by reacting one equivalent of methacryloyl chloride with aminopropyltriethoxysilane and a compound obtained by reacting two equivalents. The compound obtained by reacting two equivalents has excess methacryl groups that cannot form the stable cyclic structure described above, resulting in a poor dielectric loss tangent. Furthermore, the compound obtained by reacting two equivalents is highly hydrophobic, resulting in poor storage stability of the treatment solution. That is, the organosilicon compound containing a methacrylamide group used in the present invention is characterized by having an amino group to methacryl group ratio (molar) of 1:1.

[0034] As described above, the treatment liquid used in the present invention is substantially free of compound (2). Specific examples of compound (2) include N,N-dimethacrylamidomethyltrimethoxysilane, N,N-dimethacrylamidomethylmethyldimethoxysilane, N,N-dimethacrylamidomethyltriethoxysilane, N,N-dimethacrylamidomethylmethyldiethoxysilane, 3-(N,N-dimethacrylamido)propyltrimethoxysilane, 3-(N,N-dimethacrylamido)propylmethyldimethoxysilane, 3-(N,N-dimethacrylamido)propyltriethoxysilane, 3-(N,N-dimethacrylamido)propylmethyldiethoxysilane, 4-(N,N-dimethacrylamido)butyltrimethoxysilane, and 4-(N,N-dimethacrylamido)butylmethyldimethoxysilane.

[0043] Examples of the silane include, but are not limited to, dimethylsilane, 4-(N,N-dimethacrylamido)butyltriethoxysilane, 4-(N,N-dimethacrylamido)butylmethyldiethoxysilane, 8-(N,N-dimethacrylamido)octyltrimethoxysilane, 8-(N,N-dimethacrylamido)octylmethyldimethoxysilane, 8-(N,N-dimethacrylamido)octyltriethoxysilane, 8-(N,N-dimethacrylamido)octylmethyldiethoxysilane, 12-(N,N-dimethacrylamido)dodecyltrimethoxysilane, 12-(N,N-dimethacrylamido)dodecylmethyldimethoxysilane, 12-(N,N-dimethacrylamido)dodecyltriethoxysilane, and 12-(N,N-dimethacrylamido)dodecylmethyldiethoxysilane. When these compounds are contained, one kind may be contained alone, or two or more kinds may be contained in combination. Among these, typical examples of compound (2) are those represented by the following formula, particularly compound (2-1) or compound (2-3): In the following formula, Me represents a methyl group, and Et represents an ethyl group.

[0035] [ka]

[0036] In the treatment liquid used in the present invention, compound (1) is dissolved in water. The content of compound (1) in the silane treatment liquid is preferably 0.05 to 1 mass %, more preferably 0.1 to 1 mass %. If the content is less than 0.05 mass %, the amount of compound (1) relative to the silanol groups of the glass cloth is insufficient, and the strength of the glass cloth may not be sufficiently improved. If the content exceeds 1 mass %, the storage stability of the treatment liquid may be impaired, and further, the glass cloth may become rigid, which may reduce the productivity of the substrate material.

[0037] The treatment solution used in the present invention is preferably an aqueous solution made acidic to further enhance the dispersibility of compound (1). Examples of acids used to adjust the acidity include organic acids such as formic acid, acetic acid, and citric acid, and inorganic acids such as hydrochloric acid. When an acid is used, the amount of acid added is preferably 0.001 to 0.5% by mass, more preferably 0.01 to 0.1% by mass, of the total composition.

[0038] If necessary, an organic solvent may be added to the treatment solution of the present invention within the range that does not impair the effects of the present invention. Furthermore, in order to improve the adhesion and bonding properties to the quartz glass fiber, an alkoxy group-containing organosilicon compound other than compound (1), a silazane compound, etc. may be added.

[0039] The treatment liquid used in the present invention can be prepared by mixing compound (1), optionally an acid and other compounds, with water, and dissolving compound (1) in water.

[0040] [2] Manufacturing method for silane-treated quartz glass fiber The silane-treated quartz glass fiber of the present invention can be obtained by surface-treating the above-mentioned quartz glass fiber with the above-mentioned silane treatment solution.

[0041] In the present invention, the method for surface treatment of the quartz glass fiber is not particularly limited and may be appropriately selected from conventionally known methods. However, from the viewpoints of productivity and environmental load, the method of applying the above-mentioned treatment liquid to the quartz glass fiber is preferred. The method for applying the treatment liquid is not particularly limited, but examples include a method in which the quartz glass fiber is immersed in the treatment liquid, and a treatment by roll coating.

[0042] After treating the quartz glass fiber with the treatment solution, it is preferable to dry it. The drying method is not particularly limited, but examples include hot air drying, infrared drying, and drying using a hot roll. The drying conditions are also not particularly limited, but for example, drying at 90 to 150°C for 30 seconds to 30 minutes is suitable. Under such drying conditions, water can be evaporated and compound (1) can react with the SiOH group on the surface of the quartz glass fiber, further reducing the dielectric tangent of the quartz glass fiber.

[0043] The amount of compound (1) attached to the silica glass fiber is preferably 0.01 to 0.5 mass %, more preferably 0.05 to 0.4 mass %. Within this range, the dielectric loss tangent of the silica glass fiber can be reduced while increasing its strength. If the amount of compound (1) attached is less than 0.01% by mass, the amount of compound (1) relative to the SiOH groups on the surface of the quartz glass fiber will be insufficient, making it impossible to reduce the dielectric tangent and resulting in a failure to increase strength. If the amount of compound (1) attached exceeds 0.5% by mass, the amount of compound (1) will be excessive relative to the SiOH groups on the surface, resulting in a deterioration in the dielectric tangent and a loss of flexibility from the quartz glass fiber. In the present invention, the amount of compound (1) attached to the quartz glass fiber can be measured by the loss on ignition as described in JIS R 3420.

[0044] [3] Silane-treated quartz glass cloth The silane-treated quartz glass cloth of the present invention contains the above-mentioned silane-treated quartz glass fiber. The silane-treated quartz glass cloth of the present invention is not particularly limited in weave structure, weave density, etc., so long as it contains the above-mentioned silane-treated quartz glass fiber, and examples thereof include plain weave cloth, satin weave cloth, flat cloth, etc. Of these, plain weave quartz glass cloth is preferred in terms of confirming the effects of dielectric loss tangent and strength.

[0045] [4] Manufacturing method for silane-treated quartz glass cloth The method for producing the silane-treated quartz glass cloth of the present invention is not particularly limited, but examples include (1) a method in which the quartz glass cloth is surface-treated with a silane treatment solution, and (2) a method in which the silane-treated quartz glass fiber is woven or otherwise produced.

[0046] (1) Manufacturing method for surface treatment of quartz glass cloth (1-1) Quartz glass cloth Examples of the quartz glass cloth include the same materials as those exemplified for the silane-treated quartz glass cloth.

[0047] The quartz glass cloth used in the present invention can be obtained by weaving the above-mentioned quartz glass yarn. The basis weight of the quartz glass cloth used in the present invention is not particularly limited and can be appropriately selected within a conventionally known range, for example, 10 to 100 g / m 2 is preferred.

[0048] The weaving method is not particularly limited, and conventionally known methods can be used, including, for example, weaving methods using an air jet loom, a water jet loom, a rapier loom, a shuttle loom, etc. When weaving using an air jet loom or the like, PVA or starch can be applied as a secondary sizing agent to obtain further lubricity.

[0049] The sizing agent adheres to the surface of the woven quartz glass cloth, and if left as is, the remaining sizing agent may deteriorate the dielectric properties. Furthermore, the silane treatment of the quartz glass cloth may become insufficient, resulting in poor adhesion with the resin when used in a prepreg. Therefore, it is preferable to perform a deoiling treatment after weaving to remove the adhering sizing agent.

[0050] The deoiling treatment is not particularly limited, and conventionally known methods can be used, such as washing with water or an organic solvent, or a method called heat cleaning in which organic matter is removed by burning it. Heat cleaning is more common because it can remove oil more reliably. This heat cleaning is not particularly limited, and a conventionally known method can be used, such as a method using a flow or batch heating furnace. Since the flow method burns off the sizing agent all at once at high temperature, which can cause problems such as a decrease in the strength of the quartz glass cloth and residual sizing agent, a batch method is generally used, in which organic matter is slowly burned off at 300 to 400°C.

[0051] (1-2) Silane treatment solution The silane treatment liquid may be the same as that used for the surface treatment of the quartz glass fiber.

[0052] (1-3) Surface treatment method The surface treatment can be carried out in the same manner as for the surface treatment of quartz glass fiber. The amount of compound (1) attached to the quartz glass cloth is also the same as for the surface treatment of quartz glass fiber.

[0053] (2) Manufacturing method for weaving silane-treated quartz glass fiber (2-1) Silane-treated quartz glass fiber As the silane-treated quartz glass fiber, those mentioned above can be used.

[0054] (2-2) Types of crosses As the type of cloth, the same types as those exemplified for the silane-treated quartz glass cloth can be used.

[0055] (2-3) Weaving method The weaving method can be the same as that exemplified for the quartz glass cloth. Note that the use of a sizing agent, deoiling treatment, etc. can be carried out according to conventionally known methods, as needed.

[0056] [5] Silane-treated quartz glass nonwoven fabric The silane-treated quartz glass nonwoven fabric of the present invention contains the above-mentioned silane-treated quartz glass fibers. The silane-treated quartz glass nonwoven fabric of the present invention is not particularly limited as long as it contains the above-mentioned silane-treated quartz glass fibers, and can be suitably selected from conventionally known forms.

[0057] [6] Manufacturing method for silane-treated quartz glass nonwoven fabric The method for producing the silane-treated quartz glass nonwoven fabric of the present invention is not particularly limited, but examples include (1) a method in which a quartz glass nonwoven fabric is surface-treated with a silane treatment solution, and (2) a method in which a silane-treated quartz glass fiber is produced by papermaking or the like.

[0058] (1) Manufacturing method for surface treatment of quartz glass nonwoven fabric (1-1) Quartz glass nonwoven fabric The quartz glass nonwoven fabric is not particularly limited as long as it contains the above-mentioned quartz glass fibers, and can be appropriately selected from conventionally known forms.

[0059] The basis weight of the quartz glass nonwoven fabric used in the present invention is not particularly limited and can be appropriately selected within a conventionally known range, for example, 10 to 100 g / m 2 is preferred.

[0060] The method for producing the quartz glass nonwoven fabric is not particularly limited, and any conventionally known method can be used. Examples include a dry papermaking method in which quartz glass fibers cut to a predetermined length are used to form a web using a carding machine or the like, and a wet papermaking method in which quartz glass fibers cut to a predetermined length are dispersed in water and paper-formed to form a web.

[0061] In the dry papermaking method, for example, the above-mentioned glass strands are used as the quartz glass fibers, and are cut into lengths of preferably 10 to 100 mm, more preferably 20 to 70 mm, using a cutting machine or the like, and then opened into a web using a carding machine or the like. The obtained web can be processed into a nonwoven fabric by a method of entangling the fibers with a water flow, a method of bonding the fibers with a binder, a method of heat-fusing the fibers together, or the like. In addition, in the wet papermaking method, for example, the above-mentioned glass strands as quartz glass fibers are cut in the same manner as above and dispersed in water, and this is made into a net or the like to form a web, which is then bonded with a binder or the like to form a nonwoven fabric. The conditions for forming the web, processing, etc. can be appropriately selected from the ranges known in the art. When the obtained nonwoven fabric is subjected to a deoiling treatment, the treatment can be carried out in the same manner as described for the quartz glass cloth.

[0062] (1-2) Silane treatment solution The silane treatment liquid may be the same as that used for the surface treatment of the quartz glass fiber.

[0063] (1-3) Surface treatment method The surface treatment can be carried out in the same manner as for the surface treatment of quartz glass fibers, and the amount of compound (1) attached to the quartz glass nonwoven fabric is also the same as for the surface treatment of quartz glass fibers.

[0064] (2) Manufacturing method for producing silane-treated quartz glass fiber (2-1) Silane-treated quartz glass fiber As the silane-treated quartz glass fiber, those mentioned above can be used.

[0065] (2-2) Types of nonwoven fabrics The types of nonwoven fabric can be the same as those described for the silane-treated quartz glass nonwoven fabric.

[0066] (2-3) Paper making method The papermaking method can be the same as that exemplified for the quartz glass nonwoven fabric. The conditions for cutting, web formation, processing, etc. can be appropriately selected from conventionally known ranges as needed.

[0067] [7] Characteristics The silane-treated quartz glass cloth and silane-treated quartz glass nonwoven fabric of the present invention preferably have a dielectric loss tangent at 10 GHz that is less than 1, more preferably less than 1.0, and even more preferably 0.9 or less, compared to that before silane treatment. The dielectric loss tangent at 40 GHz is also preferably less than 1, more preferably less than 1.0, and even more preferably 0.9 or less, compared to that before silane treatment. The dielectric loss tangent of the silane-treated glass fiber of the present invention is also the same as above.

[0068] Furthermore, the silane-treated quartz glass cloth and silane-treated quartz glass nonwoven fabric of the present invention have a cloth or nonwoven fabric mass (g / mm 2 The tensile strength per unit area is preferably 1.3 times or more, and more preferably 1.4 times or more, compared to that before the silane treatment. Such a surface-treated glass cloth has excellent processability when made into a prepreg. The tensile strength can be measured in accordance with the tensile strength measurement method of JIS R 3420.

[0069] [8] Prepreg The prepreg of the present invention comprises the above-mentioned silane-treated glass cloth or silane-treated glass nonwoven fabric, and a matrix resin impregnated into the silane-treated glass cloth or silane-treated glass nonwoven fabric. The silane-treated quartz glass fiber of the present invention has a low dielectric loss tangent, and by using it, for example, a prepreg for a printed circuit board having improved dielectric properties can be obtained. The method for producing the prepreg is not particularly limited, and general methods for producing glass cloth-containing substrates, films, prepregs, etc. can be applied.

[0070] [9] Printed wiring board The printed wiring board of the present invention contains the above prepreg. The silane-treated quartz glass fiber of the present invention has a low dielectric loss tangent, and its use allows for the production of printed circuit boards with improved dielectric properties. Therefore, the printed circuit board of the present invention is suitable for use in electronic components having circuits that transmit electrical signals of 10 GHz or higher, for example. The method for manufacturing the printed circuit board is not particularly limited, and a general method for manufacturing a printed circuit board can be applied. [Example]

[0071] The present invention will be specifically explained below with reference to Production Examples, Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples. In the following formulas, Me represents a methyl group, and Et represents an ethyl group.

[0072] [1] Manufacturing of quartz glass cloth or nonwoven fabric [Manufacturing Example 1] A glass fiber sizing agent containing 3.0 mass % of starch, 0.5 mass % of beef tallow, 0.1 mass % of an emulsifier, and the remaining water was prepared. A silica glass ingot with an SiO2 content of 99.9% by mass or more was heated and drawn to produce a silica glass fiber consisting of silica glass filaments with a diameter of 5.3 μm. The silica glass fiber sizing agent was applied with an applicator, and then the fiber was bundled with a bundler and wound up to produce a silica glass strand with 200 silica glass filaments. The wound quartz glass strand was twisted at 24 T / m to produce a quartz glass yarn. The obtained quartz glass yarn was coated with an aqueous solution containing 1.5% by mass of PVA and 1.5% by mass of starch as a secondary bundling agent, and then a quartz glass plain weave cloth was produced at a weave density of IPC standard 1078 using an air jet loom ZAX9200i manufactured by Tsudakoma Kogyo Co., Ltd. The resulting woven quartz glass plain weave cloth was heated at 400°C for 72 hours in an electric furnace B80x85x200-3Z12-10 manufactured by Nems Co., Ltd. to remove the sizing agent, yielding a desized quartz glass plain weave cloth (basis weight 42 g / m2 ).

[0073] [Manufacturing Example 2] A glass fiber sizing agent containing 3.0 mass % of starch, 0.5 mass % of beef tallow, 0.1 mass % of an emulsifier, and the remaining water was prepared. A silica glass ingot with an SiO2 content of 99.9% by mass or more was heated and drawn to produce a silica glass fiber consisting of silica glass filaments with a diameter of 13.2 μm. The above-mentioned silica glass fiber sizing agent was applied with an applicator, and then the fiber was bundled with a bundler and wound up to produce a silica glass strand with 280 silica glass filaments. The wound quartz glass strand was twisted at 24 T / m to produce a quartz glass yarn. The obtained quartz glass yarn was coated with an aqueous solution containing 1.5% by mass of PVA and 1.5% by mass of starch as a secondary bundling agent, and then a quartz glass satin weave cloth was produced using a Dornier rapier loom at a weave density in accordance with IPC standard 4581. The resulting woven quartz glass satin weave cloth was heated at 400°C for 72 hours in an electric furnace B80x85x200-3Z12-10 manufactured by Nems Co., Ltd. to remove the sizing agent, and a desized quartz glass satin weave cloth was obtained (basis weight 306 g / m 2 ).

[0074] [Manufacturing Example 3] A silica glass ingot with an SiO2 content of 99.9% by mass or more was heated and drawn to produce a silica glass fiber consisting of silica glass filaments with a diameter of 5.3 μm. A silica glass fiber sizing agent was applied with an applicator, and the fiber was then bundled with a bundler and wound up to produce a silica glass strand with 200 silica glass filaments. The obtained quartz glass strands were cut in the same direction using a cutting machine equipped with a ceramic blade having a length of 50 mm. The resulting cut quartz glass strands were cut to a weight of 30 g / m 2 The fibers were opened separately in a carding machine (Sample Roller Card 30-300DR, manufactured by Yamato Kiko Co., Ltd.) with the temperature set at 100°C to prepare a carded web. The resulting carded web was fed onto a conveyor belt made of 50-mesh plastic netting, which was run at approximately 7 m / min. A water-jet processor (maximum water pressure 16 MPa, manufactured by Kawanoe Zoki Co., Ltd.) was placed along the belt's path and subjected to entanglement treatment using a high-pressure liquid columnar stream. The water-jet processor had three rows of nozzles with pore diameters of 0.08–0.1 mm and spacing of 0.6–1.0 mm, arranged in a single horizontal row perpendicular to the direction of the conveyor belt. The nozzles of the water-jet processor were positioned 2 cm apart, and water was sprayed from the three rows of water jets at a water pressure of 1.0–5.0 MPa. The sheet entangled by the above method was dried at 120°C for 1 minute using a through-dryer type dryer, and then heated at 400°C for 72 hours using an electric furnace B80×85×200-3Z12-10 manufactured by NEMS Co., Ltd. to remove the sizing agent, yielding a desized quartz glass nonwoven fabric.

[0075] [Comparative Manufacturing Example 1] A glass fiber sizing agent containing 3.0 mass % of starch, 0.5 mass % of beef tallow, 0.1 mass % of an emulsifier, and the remaining water was prepared. An E-glass ingot with an SiO2 content of 53 mass% was heated and drawn to produce an E-glass fiber consisting of E-glass filaments with a diameter of 5.3 μm. The above-mentioned glass fiber sizing agent was applied with an applicator, and then the fiber was bundled with a bundler and wound up to produce an E-glass strand with 200 E-glass filaments. The wound E-glass strand was twisted at 24 T / m to produce an E-glass yarn. The obtained E-glass yarn was coated with an aqueous solution containing 1.5% by mass of PVA and 1.5% by mass of starch as a secondary bundling agent, and then an E-glass cloth was produced with a weave density of IPC standard 1078 using an air jet loom ZAX9200i manufactured by Tsudakoma Kogyo Co., Ltd. The obtained E-glass cloth was heated at 400°C for 72 hours in an electric furnace B80x85x200-3Z12-10 manufactured by Nems Co., Ltd. to remove the sizing agent, and a desized E-glass cloth (basis weight 48 g / m 2 ).

[0076] [2] Synthesis of organosilicon compounds [Synthesis Example 1] With reference to Japanese Patent No. 3561501, a methacrylamide group-containing organosilicon compound (1-1) represented by the following formula was obtained.

[0077] [ka]

[0078] [Synthesis Example 2] With reference to Japanese Patent No. 3561501, a methacrylamide group-containing organosilicon compound (1-3) represented by the following formula was obtained.

[0079] [ka]

[0080] [Comparative Synthesis Example 1] With reference to JP-A-5-25219, a mixture (3-1) of a methacrylamide group-containing organosilicon compound and a dimethacrylamide group-containing organosilicon compound represented by the following average formula was obtained.

[0081] [ka]

[0082] [3] Manufacturing of silane-treated quartz glass cloth [Example 1] An aqueous silane treatment solution containing 0.2 mass % of the methacrylamide group-containing organosilicon compound (1-1) obtained in Synthesis Example 1 and 0.1 mass % of acetic acid was prepared. The desized quartz glass plain weave cloth obtained in Production Example 1 was impregnated with the resulting silane treatment aqueous solution and dried at 110°C for 10 minutes in a Yamato Scientific constant temperature incubator DKN602 to perform silane treatment.

[0083] [Example 2] Silane treatment was carried out in the same manner as in Example 1, except that an aqueous silane treatment solution containing 1% by mass of the methacrylamide group-containing organosilicon compound (1-1) obtained in Synthesis Example 1 and 0.1% by mass of acetic acid was prepared.

[0084] [Example 3] Silane treatment was carried out in the same manner as in Example 1, except that an aqueous silane treatment solution containing 0.1 mass % of the methacrylamide group-containing organosilicon compound (1-1) obtained in Synthesis Example 1 and 0.1 mass % of acetic acid was prepared.

[0085] [Example 4] Silane treatment was carried out in the same manner as in Example 1, except that an aqueous silane treatment solution containing 0.2 mass % of the methacrylamide group-containing organosilicon compound (1-3) obtained in Synthesis Example 2 and 0.1 mass % of acetic acid was prepared.

[0086] [Example 5] The silane treatment was carried out in the same manner as in Example 1, except that the desized quartz glass satin cloth obtained in Production Example 2 was used.

[0087] [Example 6] Silane treatment was carried out in the same manner as in Example 1, except that the desized quartz glass nonwoven fabric obtained in Production Example 3 was used.

[0088] [Comparative Example 1] Silane treatment was carried out in the same manner as in Example 1, except that an aqueous silane treatment solution containing 0.2 mass % of the methacrylamide group-containing organosilicon compound (3-1) obtained in Comparative Synthesis Example 1 and 0.1 mass % of acetic acid was prepared.

[0089] Comparative Example 2 Silane treatment was carried out in the same manner as in Example 1, except that an aqueous silane treatment solution containing 0.2 mass % of KBM-903 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was prepared.

[0090] Comparative Example 3 Silane treatment was carried out in the same manner as in Example 1, except that an aqueous silane treatment solution containing 0.2 mass % of KBM-503 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.1 mass % of acetic acid was prepared.

[0091] Comparative Example 4 Silane treatment was carried out in the same manner as in Example 1, except that the desized E glass cloth obtained in Comparative Production Example 1 was used.

[0092] [4] Characterization The glass cloths or nonwoven fabrics obtained in the examples and comparative examples were evaluated by the following methods. The dielectric loss tangent and tensile strength were measured for the glass cloths or nonwoven fabrics before and after the silane treatment. The results are shown in Tables 1 and 2 below.

[0093] 1. Measurement of dielectric loss tangent The dielectric loss tangent of the glass cloth or nonwoven fabric at 10 GHz and 40 GHz was measured using a cavity resonator (TE011 mode) manufactured by AET Corp. The thickness of the glass cloth or nonwoven fabric was measured using the theoretical film thickness, which is calculated using the following formula: Theoretical film thickness t (μm) = Area weight (g / m 2 ) / specific gravity (g / cm 3 ) was calculated from 2. Tensile strength Measurement was carried out using an autograph AGS-X manufactured by Shimadzu Corporation in accordance with the tensile strength measurement method of JIS R 3420. 3. Amount of organic silicon compound attached Measurement was carried out in accordance with the ignition loss measurement method of JIS R 3420. 4. Reliability evaluation of the board To 100 parts by mass of SLK-3000 (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.), 2 parts by mass of dicumyl peroxide (trade name: Percumyl D, manufactured by NOF Corporation) was added, and the mixture was added to toluene as a solvent and premixed with a stirrer to prepare a resin varnish. The silane-treated glass cloth or nonwoven fabric (silane-treated glass fiber) obtained in the Examples and Comparative Examples was impregnated with the prepared resin varnish and dried at 110°C for 10 minutes to prepare a prepreg. The amount of resin varnish applied was adjusted to 55% by mass. Three prepared prepregs were then stacked and cured using a vacuum press at 150°C for 1 hour and then at 180°C for 2 hours to prepare a substrate. The obtained substrate was boiled in ion-exchanged water for 1 hour and then immersed in a solder bath at 260°C for 30 seconds. The substrate was removed from the solder bath and visually observed. Those that did not blister were evaluated as "Good", and those that blistered were evaluated as "Poor".

[0094] [Table 1]

[0095] [Table 2]

[0096] As shown in Table 1, when the quartz glass fibers are treated with the methacrylamide group-containing organosilicon compounds of Examples 1 to 6, the dielectric loss tangent of the quartz glass cloth and quartz glass nonwoven fabric can be further reduced at frequencies of 10 GHz and 40 GHz by silane treatment, and the strength can be increased by 1.3 times or more. In the compound 3-1 of Comparative Example 1, there was no problem with the strength, but the dielectric loss tangent was deteriorated because the methacryl groups were in excess relative to the amino groups. In the amino group-containing KBM-903 of Comparative Example 2, not only did the dielectric loss tangent deteriorate, but the strength increase rate was also insufficient at less than 1.3 times. In the case of KBM-503 containing a methacryl group in Comparative Example 3, although the strength increase rate is sufficient, the dielectric loss tangent deteriorates. Furthermore, in the E-glass of Comparative Example 4, even if the methacrylamide group-containing organosilicon compound of the present invention is used, the dielectric loss tangent of the E-glass itself is too large, so the effect of the methacrylamide group-containing organosilicon compound in reducing the dielectric loss tangent is not exerted. When the quartz glass fiber treated with the methacrylamide group-containing organosilicon compound of the present invention is made into a prepreg or a substrate, sufficient reliability is obtained, similar to the silane coupling agents of Comparative Examples 1 to 3.

[0097] According to the present invention, it is possible to provide a silane-treated quartz glass fiber that further reduces the dielectric loss tangent of the quartz glass fiber in the high frequency band and has excellent strength. The quartz glass cloth and quartz glass nonwoven fabric made from this silane-treated quartz glass fiber not only stably reduces the transmission loss of substrates for 5G and 6G communication applications in the high frequency band, but also enables the line speed of substrate production to be increased more than ever before, thereby achieving the significant effect of meeting the demand for substrates for 5G and 6G communication applications. The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention.

Claims

1. SiO 2 A silane-treated quartz glass cloth containing silane-treated quartz glass fibers that have been surface-treated with a silane treatment solution in which the methacrylamide group-containing organosilicon compound represented by the following formula (1) is present in a content of 95% by mass or more, the methacrylamide group-containing organosilicon compound represented by the following formula (1) is dissolved in water, and the content of the dimethacrylamide group-containing organosilicon compound represented by the following formula (2) is less than 1 part by mass per 100 parts by mass of the methacrylamide group-containing organosilicon compound represented by the following formula (1), A silane-treated quartz glass cloth in which a methacrylamide group-containing organosilicon compound is adhered in an amount of 0.01 to 0.5 mass % relative to the quartz glass cloth. 【Chemical 1】 (In the formula, R 1 each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, Me represents a methyl group, m1 and m2 represent integers of 1 to 3, and n1 and n2 represent integers of 1 to 12.

2. 2. The silane-treated quartz glass cloth according to claim 1, wherein the dielectric loss tangent at 10 GHz is less than 1 times that before the silane treatment.

3. 2. The silane-treated quartz glass cloth according to claim 1, wherein the dielectric loss tangent at 40 GHz is less than 1 times that before the silane treatment.

4. 2. The silane-treated quartz glass cloth according to claim 1, wherein the tensile strength is at least 1.3 times that of the quartz glass cloth before the silane treatment.

5. A prepreg comprising the silane-treated quartz glass cloth according to any one of claims 1 to 4 and a matrix resin impregnated into the silane-treated quartz glass cloth.

6. A printed wiring board comprising the prepreg according to claim 5.

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