JP2011246595A - Glass fiber-reinforced composite material and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass fiber-reinforced composite material increased in adhesion and mechanical strength and obtained by forming a dry prepreg, laminating plural dry prepreg, and monolithically molding under high temperature and pressurized conditions, wherein the dry prepreg is produced by using a polyvinyl chloride resin as the matrix resin and the resin is affixed to the surface of and inside the fiber bundles of, glass fiber-woven fabrics, as the reinforcing fiber.SOLUTION: The glass fiber-reinforced composite material is, for example, prepared by: immersing a glass fiber-woven fabric of the reinforcing fiber in a resin solution prepared by previously dissolving a matrix resin in an organic solvent, and drying the obtained material to prepare the dry prepreg impregnated with the matrix resin in the fiber bundle; immersing the prepreg in the resin solution again; then, laminating plural sheets of products obtained by adhering the resin solution to the dry prepreg surface and drying it; pressurizing the resulting material in a condition of a temperature of the softening point of the matrix resin or higher; and cooling and curing the resultant material.

Description

The present invention relates to a glass fiber reinforced thermoplastic composite material having glass fiber as a reinforcing material and a thermoplastic resin as a base material (matrix).

  Conventionally, many studies have been made to add mechanical strength and heat resistance by blending an inorganic filler into a thermoplastic resin, and it has been put to practical use.

  As an example of the thermoplastic resin, for example, a polyvinyl chloride (PVC) resin is a resin excellent in chemical resistance, electrical insulation and the like, and since it is inexpensive, films, fibers, various pipes, It is widely used in a wide range of joints, building materials, corrugated sheets, and other shaped products.

  PVC having such characteristics is generally known to contain inorganic fillers such as needle-like inorganic materials or plate-like inorganic clays, calcium carbonate, and glass fibers in order to further improve mechanical properties. It has been. However, when using inorganic clays such as talc, mica, etc. as fillers as acicular inorganic materials such as calcium silicate, potassium titanate, basic magnesium sulfate, sepiolite, zonotlite, aluminum borate, etc. There is a problem that the reinforcing effect is small, and a large amount of blending is required to sufficiently improve the mechanical strength, thereby reducing impact resistance and toughness. On the other hand, when glass fiber is used as a filler, not only weight reduction and strength improvement but also many requirements such as electrical insulation and workability can be realized. Examples thereof include chopped strands in the form of fibers, which are known as pellet-shaped molded products or stampable sheets in which short glass fibers are mixed by injection molding or extrusion molding.

  As composite materials using continuous glass fibers, for example, molded products such as corrugated sheet materials and curtain materials in a shape in which a lattice (mesh) woven fabric with a small basis weight is sandwiched between sheet-like vinyl chloride resins are known. In addition, after passing continuous unidirectional glass fiber through the powdery PVC resin and attaching the resin to the reinforcing fiber, it is continuously heated and melted and integrated with the reinforcing fiber. Molded articles are also known. Also known is a method in which glass fibers having a woven shape are preliminarily placed in a mold and integrated by melting and extruding PVC. Glass fibers comprising hundreds to tens of thousands of monofilaments are known. When the woven material is used as the reinforcing fiber, the viscosity of the PVC resin melted at a high temperature is large. Therefore, the reinforcing fiber is caused to flow along with the flow of the resin, and the woven material is broken. There is a problem that the inside is not sufficiently impregnated, voids (voids) are generated, and the mechanical strength tends to be lowered. In addition, when hot pressing is performed for a long time to eliminate voids, there is a problem that the resin and the reinforcing fiber are thermally deteriorated, and the strength and the like of the composite material are lowered.

  In addition, the glass fiber surface is functionalized by plasma treatment, ozone treatment, corona treatment, and chemical etching treatment to attach a sizing agent suitable for PVC resin, or by adding an additive to the interface. However, there are problems such as an increase in the number of processes and an increase in manufacturing cost, damage to the glass fiber itself, and a reduction in the strength of the composite material.

JP 2005-299047 A JP-A-1987-156359 JP 1991-158211 JP 1991-158211 JP 1998-278121 A JP 2010-52370 A

  A dry prepreg with a polyvinyl chloride resin as a matrix resin and a resin attached to the inside and surface of a monofilament bundle of glass fiber fabric as a reinforcing fiber is manufactured and laminated in a single piece under high temperature and pressure conditions. A glass fiber reinforced composite material with improved adhesiveness and mechanical strength, which is free from disruption of textile fibers, is provided.

As a result of intensive studies on such problems, the present invention has been completed. That is, the present invention has the following configuration.
(1) Apparent interlayer measured by a short beam shear test method by three-point bending based on ASTM-D2344 using a polyvinyl chloride resin as a matrix resin and glass fibers having a woven fabric shape made of monofilament bundles as reinforcing fibers. A glass fiber reinforced composite material having a shear strength of 20 MPa or more at 25 ° C.
(2) A resin solution in which a matrix resin is dissolved in an organic solvent in advance is impregnated with a glass fiber fabric and dried to prepare a dry prepreg in which the matrix resin is impregnated in the monofilament bundle and on the bundle surface. After pressurizing under the temperature condition above the softening point of the matrix resin in a state where a plurality of layers obtained by impregnating the resin solution again to adhere the resin solution to the surface of the dry prepreg and drying it are laminated. The glass fiber reinforced composite material according to (1), which is prepared by cooling and curing.
(3) A glass fiber fabric is impregnated in a resin solution in which a matrix resin is dissolved in an organic solvent in advance and dried to prepare a dry prepreg in which the matrix resin is impregnated in the monofilament bundle and on the bundle surface. The glass fiber reinforced composite material according to (1), which is produced by pressurizing under a temperature condition equal to or higher than the softening point of the matrix resin in a state where a plurality of matrix resins are alternately laminated, and then cooling and curing. .
(4) The glass fiber reinforced composite material according to any one of (1) to (3), wherein the weight content of the matrix resin is 20% to 60%.

According to the present invention, it is possible to obtain a glass fiber reinforced composite material made of continuous glass fibers and a polyvinyl chloride resin, which has improved mechanical properties and has no collapse of textile fibers.

  The present invention is described in detail below.

  The glass composition of the glass fiber applied to the present invention is E glass (non-alkali glass composition), AR glass (alkali resistant glass composition), C glass (acid resistant alkali lime-containing glass composition), D glass (low dielectric constant). The composition to be realized) can be applied, but E glass is preferable.

  Furthermore, in addition to glass fibers, organic synthesis such as inorganic fibers such as other types of carbon fibers, metal fibers, and ceramic fibers, polyamide fibers, polyester fibers, polyolefin fibers, and novoloid fibers, to the extent that the effects of the present invention are not impaired. A combination of fibers can be used.

  The glass fiber used for the glass fiber woven material has a strand (toe) shape in which a plurality of monofilaments are converged, but the number of monofilaments is not particularly limited, and is preferably several hundred to several tens of thousands, More preferably, it is several hundred to several thousand.

  Moreover, as long as the form of the fiber material constituting the fiber reinforced composite material is a continuous fiber-shaped structure by weaving (plain weaving, twill weaving, satin weaving, tangle weaving, imitation weaving, oblique weaving, double weaving, etc.) It is not particularly limited and may be appropriately selected according to the purpose, and these can be used alone or in combination. In general, the glass fiber is subjected to a sizing treatment. In the present invention, it is desirable to remove the sizing before the implementation of the present invention, if necessary.

The basis weight of the reinforcing fiber applied to the present invention is preferably 50 to 400 g / m ² , more preferably 100 to 300 g / m ² . When the basis weight of the reinforcing fiber is less than 50 g / m ² , the resin solution is not sufficiently adhered, and the resin detachment is likely to occur in the dried prepreg after drying. When the basis weight of the reinforcing fiber exceeds 400 g / m ² , At the time of impregnation, the resin does not reach the central part in the thickness direction, and a fiber-reinforced composite material in which an unimpregnated part (void) remains remains, which may cause a decrease in mechanical properties.

  The polyvinyl chloride resin applied to the present invention refers to a resin containing 50% by weight or more of a repeating unit derived from a vinyl chloride monomer. In the polyvinyl chloride resin of the present invention, the repeating unit amount derived from the vinyl chloride monomer is preferably 60% by weight or more, more preferably 75% by weight or more, and 90% by weight or more. Further preferred. The polyvinyl chloride resin of the present invention is typically produced by radical polymerization of a vinyl chloride monomer, and is not particularly limited. However, vinyl chloride alone or a copolymer with a copolymer capable of copolymerizing with vinyl chloride can be used. A polymer is included. For example, unsaturated dibasic acids such as vinyl esters of organic acids, vinylidene fluorofluoride, vinylidene chloride, symmetric dichloroethylene, acrylonitrile, methacrylonitrile, alkyl acrylate esters, alkyl methacrylate esters, dibutyl fumarate, and diethyl malate And copolymers with dialkyl esters, unsaturated hydrocarbons, aryl compounds, conjugated and cross-conjugated ethylenically unsaturated compounds, and the like. Such copolymers include linear copolymers, branched copolymers, graft copolymers, block copolymers, and the like.

  The molecular weight of the polyvinyl chloride resin applied to the present invention is not particularly limited as long as it does not impair the characteristics of the composite material produced in the present invention. Preferably, the molecular weight is 5,000 to 100,000. It is a polymer.

  Although it does not specifically limit as a form of the polyvinyl chloride resin to apply, A powder form, a pellet form, a film form, plate shape, and a powder form are used.

  The polyvinyl chloride resin applied to the present invention includes a heat stabilizer, an antioxidant, a metal deactivator, a phosphorus processing stabilizer, an ultraviolet absorber, an ultraviolet stabilizer, and a fluorescent brightening agent as necessary. Stabilizers such as metal soap and antacid adsorbents, or additives such as cross-linking agents, chain transfer agents, nucleating agents, lubricants, plasticizers, fillers, reinforcing materials, pigments, dyes, flame retardants, antistatic agents, etc. You may add within the range which does not impair the effect of this invention.

  The method of mixing the vinyl chloride resin and the above-mentioned stabilizer or the like is not particularly limited. For example, the vinyl chloride resin is physically mixed with the vinyl chloride resin powder, dissolved in an organic solvent, or melted. It may be kneaded in a (softened) state or added at the time of molding the composite material.

  The method for producing the composite material of the glass fiber and the matrix resin is not particularly limited.

  As an example of the production method, first, one or a plurality of glass fiber fabrics are impregnated in a solution in which a matrix resin is dissolved in an organic solvent in advance, and then taken out and then heated at room temperature or under normal pressure or reduced pressure. While drying, a dry prepreg having a resin adhered in the glass fiber bundle is produced. If it is necessary to attach the resin to the surface of the dry prepreg, repeat the operation of re-impregnation and drying in an organic solvent with the same resin concentration or a different resin concentration, or insert a matrix resin such as powder or film between layers By laminating dry prepregs, etc., using a press machine, laminator molding machine, etc., softening the resin adhering to the dry prepregs under high temperature conditions, integrating by pressurization, cooling and curing by a method It can be carried out.

  The concentration of the resin solution when the glass fiber fabric is impregnated with the resin solution is not particularly limited, but a concentration with a low solution viscosity that can sufficiently replace the air present in the fiber bundle with the resin solution is desirable. In addition, the resin solution concentration when the obtained dry prepreg is impregnated with the resin solution again and the resin is adhered to the surface of the dry prepreg is not particularly limited, and the amount of resin in the dried prepreg after drying is not limited. Adjustment may be made for appropriate adjustment, and repeated impregnation and drying operations may be performed.

  The type of organic solvent used in preparing the dry prepreg is not particularly limited as long as it dissolves the vinyl chloride resin, and examples thereof include tetrahydrofuran, cyclohexanone, dioxane, dimethylformamide, and the like. It is done.

  The amount of the solvent contained in the prepared dry prepreg is not particularly limited, but it does not generate voids in the composite material obtained by pressure molding using the dry prepreg and does not reduce the mechanical strength. The amount may be sufficient, but it is preferable to contain no solvent as much as possible.

  In addition, as a composite material production method, the resin is softened under high temperature conditions using a press machine, laminator molding machine, etc. after alternately laminating glass fiber plain weave and vinyl chloride resin without using a solvent. And a method of cooling and curing after pressurizing and integrating. The obtained composite material can be further laminated and integrated under high temperature and pressure conditions.

  In producing the glass fiber reinforced composite material of the present invention, the number of dry prepregs to be laminated is not particularly limited, but is preferably 5 or more, and more preferably 10 or more. The number of dry prepregs is usually 100 or less.

  When producing the glass fiber reinforced composite material of the present invention, the temperature at which the softened matrix resin is impregnated into the glass fiber and the dry prepregs are integrated is particularly limited as long as the temperature is equal to or higher than the melting point of the matrix resin. However, it is preferably 160 ° C. or higher, more preferably 180 ° C. or higher. The temperature at which the dry prepregs are integrated is usually 500 ° C. or lower.

  When the fiber reinforced composite material of the present invention is produced, the pressure condition when the softened matrix resin is impregnated into glass fibers and the dry prepregs are integrated is preferably a pressure of 1 MPa or more, more preferably Is 10 MPa or more, more preferably 20 MPa or more. The pressure condition is usually 500 MPa or less.

  The shape of the glass fiber composite material obtained in the present invention is not particularly limited, but is formed into various shapes by a mold, for example, flat plate shape, convex shape, concave shape, T shape, Z Examples of the shape include a mold shape and an I shape, and examples of the shape include a hole in order to perform mechanical coupling using a bolt or a rivet.

  The resin content contained in the glass fiber reinforced composite material is preferably 10 to 60% by weight, more preferably 20 to 60% by weight, and still more preferably 20 to 50% by weight. When the resin content exceeds 60% by weight, it may not be suitable for weight reduction. When the resin content is less than 10% by weight, voids may remain in the composite material because the amount of the resin is small, and mechanical properties may deteriorate.

  The apparent interlaminar shear strength of the glass fiber composite material obtained in the present invention is determined by cutting the vicinity of the center of the produced laminate in accordance with the short beam shear test method by three-point bending of the composite material based on ASTM-D2344. As a result, it is defined as the apparent interlaminar shear strength because it may occur along with the interlaminar shear fracture at the interface as well as other fracture modes such as compression fracture and tensile fracture of the resin. However, the apparent interlaminar shear strength is preferably 20 MPa or more, and more preferably 25 MPa or more in order to withstand practical use. The apparent interlayer shear strength is usually 300 MPa or less.

The following examples are provided to illustrate the invention, but are not intended to limit the invention. The raw materials used and the measurement conditions for each characteristic were as follows.
<Matrix resin>
Kaneka Polyvinyl Chloride Resin (trade name: Kane Vinyl S-400 (average polymerization degree: 480)
<Stabilizer>
Nitto Kasei Methyl Tin Liquid Stabilizer Product Name: AT-1500
<Glass fiber>
Hanguk Fiber glass fiber plain weave material (trade name: G618, fiber basis weight: 200 g / m ² )
<Measurement of interlaminar shear strength of glass fiber composites>
This was performed according to ASTM-D2344.
<Method for producing glass fiber composite material>

Example 1
After 100 parts of Kane Vinyl S-400 and 3 parts of AT-1500 were uniformly mixed with a powder stirrer, they were uniformly kneaded while being softened at 165 ° C. with a calendering machine to prepare a sheet having a thickness of about 700 μm. This was uniformly dissolved in THF to prepare a 15 to 20 wt% THF solution, which was transferred to a stainless steel container. The surface of a glass fiber plain weave material (about 10 cm square) was previously washed with THF and dried, soaked in a THF solution of the above polyvinyl chloride resin, taken out for 30 minutes with an air dryer under normal pressure, A dry prepreg was prepared. The above operation was performed on 12 sheets of plain glass fiber material, and the average amount of resin in the obtained dry prepreg was about 27%. Further, the 12 produced dry prepregs were again immersed in the resin solution, taken out and dried. The average resin amount of the dry prepreg obtained by further attaching the resin by the above operation was about 42% by weight.

  Stainless steel spacer (thickness 1 cm, thickness 2 cm, 6.5 cm square) with a hole (thickness 1 cm, 6.5 cm square) in the center on a stainless steel plate (thickness 1 cm, 10 cm square) having a convex shape (thickness 2 cm, 6.5 cm square) 10 cm square). A tetrafluoroethylene sheet was placed in the hole as a release film, and 12 sheets of dry prepreg having an average resin amount of about 42% by weight produced above were laminated thereon.

  Furthermore, a tetrafluoroethylene sheet is laminated on the upper part, and a press plate machine (1 mm thick, 10 cm square) having a convex shape (thickness 6 mm, 6.5 cm square) is engaged and heated in advance ( After the mold temperature reaches 180 ° C., compression molding is performed at a pressure of 20 MPa for 5 minutes, and cooling and curing is performed. A -3 mm plate-like glass fiber composite material was obtained. The results are shown in Table 1.

(Example 2)
The same procedure as in Example 1 was performed, except that the dry prepreg having an average resin amount of about 42% by weight finally obtained in Example 1 was further subjected to immersion and drying operations in the resin solution. . The average amount of resin in the finally obtained dry prepreg was 57% by weight. The results are shown in Table 1.

(Example 3)
A THF solution having a PVC resin concentration of 15 to 20 wt% produced in the same manner as in Example 1 was transferred to a stainless steel container. The surface of a glass fiber plain weave material (about 10 cm square) was previously washed with THF and dried, soaked in a THF solution of the above polyvinyl chloride resin, taken out for 30 minutes with an air dryer under normal pressure, A dry prepreg was prepared. The above operation was performed on 12 sheets of plain glass fiber material. The average resin amount in the obtained dry prepreg was about 32%.

  The above-prepared THF solution of Kanevinyl S-400 having a resin concentration of 15 to 20 wt% is cast on a glass substrate and dried in an air circulation oven for 30 minutes, whereby a PVC having a thickness of about 30 μm is obtained. A film was obtained.

  Using the same mold as in Example 1, a sheet made of tetrafluoroethylene was placed in the hole, and the resin film (6.5 cm square) of Kane Vinyl S-400 prepared above was prepared from above. Dry prepregs (6.5 cm square) were alternately stacked, and the film layers of the polyvinyl chloride resin were laminated so that a total of 13 layers and 12 dry prepreg layers were formed. The weight of polyvinyl chloride was 40% by weight based on the total weight including the weight contained in the dry prepreg and the weight of the film.

  Thereafter, a tetrafluoroethylene sheet and a stainless steel plate having the same convex shape as in Example 1 were further engaged, and high-temperature compression integrated molding was performed with a press molding machine (molding temperature 180 ° C., pressure 20 MPa, time 5 minutes), followed by cooling and curing. By doing so, a plate-like glass fiber composite material having a thickness of about 2-3 mm with no disruption of the fiber fabric was obtained. The results are shown in Table 1.

(Comparative Example 1)
Using Kane Vinyl S-400 having a sheet shape obtained in the same manner as in Example 1 and having a thickness of about 700 μm, press molding was performed for 5 minutes under the conditions of a temperature of 180 ° C. and a pressure of 20 MPa, and a thickness of about 200 μm. Kane Vinyl S-400 film was produced. Using the same mold as in Example 1, a Teflon sheet (Teflon is a registered trademark) is placed in the mold, and a polyvinyl chloride film having a thickness of about 200 μm and a glass fiber plain weave are alternately formed thereon. The film layers of the polyvinyl chloride resin were laminated so that a total of 13 layers and a glass fiber plain weave layer had 12 layers. The weight of polyvinyl chloride was 40% by weight based on the total weight.

  Further, a tetrafluoroethylene sheet and a stainless steel plate having the same convex shape as in Example 1 were engaged with each other and further integrated by high-temperature pressure molding under the same conditions to obtain a glass fiber reinforced composite material. In the obtained composite material, part of the woven fiber was broken in the end direction along with the flow of the resin.

  Table 1 summarizes the resin amount of the dry prepreg, the resin amount of the glass fiber composite material, the fiber volume content, and the apparent interlayer shear strength in Examples 1 to 3 and Comparative Example 1.

  The laminated sheets of glass fiber reinforced composite materials obtained in Examples 1 to 3 had practically sufficient interlayer shear strength. On the other hand, the laminate obtained by Comparative Example 1 did not have sufficient strength and interlayer shear strength. Therefore, from these comparisons, it is clear that the glass-reinforced composite material obtained by the present invention is excellent in adhesiveness and mechanical strength.

Claims (4)

Apparent interlayer measured by a short beam shear test method by a three-point bending of a composite material based on ASTM-D2344 using a polyvinyl chloride resin as a matrix resin and a glass fiber having a woven fabric shape made of a monofilament bundle as a reinforcing fiber. A glass fiber reinforced composite material having a shear strength of 20 MPa or more at 25 ° C. A glass fiber fabric is impregnated in a resin solution in which a matrix resin is dissolved in an organic solvent in advance, and dried to prepare a dry prepreg in which the matrix resin is impregnated in the monofilament bundle and on the bundle surface. The resin solution obtained by impregnating inside and adhering the resin solution to the surface of the dry prepreg, and drying, after being pressed under a temperature condition equal to or higher than the softening point of the matrix resin in a stacked state, cooling, The glass fiber reinforced composite material according to claim 1, which is produced by curing. A glass fiber fabric is impregnated in a resin solution in which a matrix resin is dissolved in an organic solvent in advance and dried to prepare a dry prepreg in which the matrix resin is impregnated in the monofilament bundle and on the bundle surface. 2. The glass fiber reinforced composite material according to claim 1, wherein the glass fiber reinforced composite material is produced by pressurizing under a temperature condition equal to or higher than the softening point of the matrix resin in a state where a plurality of layers are alternately laminated, and then cooling and curing. The glass fiber reinforced composite material according to any one of claims 1 to 3, wherein a weight content of the matrix resin is 20% to 60%.