JP5429687B2 - Manufacturing method of glass chopped strand mat - Google Patents

Description

  The present invention relates to a glass chopped strand mat used as a constituent material of a fiber reinforced composite material, a method for producing the same, and a roof liner used for an automobile or the like configured by the glass chopped strand mat.

  The glass chopped strand mat is a material that has mass productivity and excellent mechanical strength and is easily available economically, and is therefore used as a constituent material for many fiber-reinforced composite materials. The glass chopped strand mat is a glass base material in which glass chopped strands are bonded to each other by an organic resin material called a binder and formed into a mat shape, and the specific production thereof is as follows. First, a glass raw material prepared to have a predetermined composition is heated and melted to obtain a homogeneous molten glass. Next, the molten glass is continuously drawn out in a thread form from a plurality of nozzles made of noble metal and cooled. A glass strand having a predetermined thickness is obtained by applying a bundling agent prepared by mixing and adjusting a plurality of agents in advance to the surface of the glass filament thus obtained, and bundling and bundling the plurality of glass filaments to which the bundling agent has adhered. . For example, in the case of a glass fiber having an E glass composition, the glass fiber may have a single fiber diameter of 11 μm and a strand count of 25 tex (tex is a mass in grams per 1000 m of length).

Thereafter, the glass strand is cut into a predetermined length by a cutting device, and a large number of the glass strands are deposited evenly and randomly to form a sheet-like deposit. For example, the length dimension of the glass strand may be cut with a glass fiber cutting cutter so as to be about 50 mm, and deposited uniformly and randomly so that the basis weight is 50 to 900 g / m ² . Then, an appropriate amount of powdered polyester resin is dispersed as a binder from above the sheet-like deposit. What is necessary is just to spread | disperse so that the adhesion amount of powder polyester resin may be 1-20 mass%. The glass chopped strand mat is obtained by heating the sheet-like deposit in which the powdered polyester resin is dispersed in this manner, softening the powdered polyester resin, and then solidifying it by cooling and solidifying the glass chopped strands. It will be.

  Glass chopped strands are used as a constituent material for many fiber reinforced composites. For example, when used as a molded ceiling material for automobiles or the like (hereinafter referred to as a roof liner), a roof liner is manufactured by bonding glass chopped strand mats to both surfaces of a foamed resin sheet. The performance required of the roof liner is to reduce the weight of the entire automobile in addition to characteristics such as rigidity, dimensional stability, heat insulation, and sound insulation. Therefore, the glass chopped strand mat used for the roof liner is required to reduce its weight per unit area, that is, to reduce the mass per unit area. However, as the basis weight of the glass chopped strand mat becomes smaller, the strand distribution of the glass chopped strand mat becomes non-uniform, so that the tensile strength (also referred to as tensile strength), which is an indicator of the mechanical strength of the mat, decreases. It becomes. As a result, after the mat is wound around the core, the mat is pulled from the outer layer in order, and the mat is broken during the so-called unwinding process. There is a problem that workability is greatly reduced because the work is performed while paying.

  For this reason, attempts to improve the mechanical strength of the chopped strand mat have been made so far. Patent Document 1 discloses that by using two types of glass chopped strands in combination, the dispersibility of the glass chopped strands on the conveyor is improved, and a glass chopped strand mat with high tensile strength is obtained. ing.

Patent Document 2 is a glass having a basis weight of 80 to 200 g / m ² and having an ignition loss according to JIS R3420 of 10 to 25% by weight, which is lightweight and does not break during unraveling work. A chopped strand mat is disclosed.

  Patent Document 3 also discloses an invention that has sufficient tensile strength and improves formability by using a binder containing 5% by mass or more of polyethylene resin as a binder for bonding glass chopped strands to each other. Has been.

Japanese Patent Laid-Open No. 6-93546 JP 2003-175777 A JP 2008-038297 A

  In the glass fiber mat as described above, after glass chopped strands are deposited on the transport net of the transport conveyor, a granular binder (also called a binder or a secondary binder) is spread on the strand deposits from above. Then, it is manufactured by cooling and solidifying after heating and melting in a heating furnace. Part of the dispersed granular binder falls down through the gap between the glass chopped strands where the strand deposits are deposited and the gap between the transport nets. As described above, when a part of the binder originally dispersed for bonding the glass chopped strands is not effectively used for bonding the glass chopped strands, the obtained glass chopped strands do not have sufficient tensile strength. There is also. For this reason, the strand deposit was previously wetted with water before the binder was sprayed, and measures were taken to make it easier for the binder to adhere to the strand deposit.

  However, even if the water-containing strand deposit wetted with water is used, a part of the sprinkled binder will fall down from the gap of the transport net while still containing water. For this reason, if it is difficult to obtain a uniform sprayed state and uniform spraying is not possible, there is a problem that the tensile strength of the glass chopped strand mat does not become uniform and becomes locally weak.

  For example, the roof liner is one of fiber reinforced composite materials using the above-described glass chopped strand mat. Regarding the glass chopped strand mat used in this roof liner, if the binder used is not evenly spread and adhered, the tensile strength of the glass chopped strand mat may be biased and the mat may be partially broken. is there. A glass chopped strand mat having a low tensile strength may break if it is continuously drawn from a rolled mat that is wound into a roll when used with other materials in the manufacturing process of a roof liner. There is. Also, if a glass chopped strand mat that is evenly dispersed and adhered is not used, it is called a sink at a corner corresponding to a deep drawing part such as a shade of an automobile ceiling when it is press-molded into the shape of an automobile ceiling. There is also a problem associated with the drawback of wrinkling of the epidermis.

  The present invention has been made in view of the various circumstances described above, and after securing the necessary rigidity to the obtained roof liner, when the glass chopped strand mat is pulled out from the mat winding body and used, the mat is flexible. In addition, it is excellent in strength, can be prevented from being partially broken or damaged, and can sufficiently suppress the appearance defects called sink marks in the roof liner using the mat. It is an object to provide a glass chopped strand mat manufacturing method, a glass chopped strand mat obtained by this manufacturing method, and a roof liner using the glass chopped strand mat of the present invention.

The method for producing a glass chopped strand mat of the present invention is a method for bonding glass chopped strands by cooling and solidifying a softened binder after spraying and heating a binder on a sheet-like deposit of glass chopped strands. A method for producing a chopped strand mat, wherein the binder has an effective particle size D ₅₀ (average particle size) of 275 μm or more and 325 μm or less, D ₁₀ of 240 μm or more, and D ₉₀ of 390 μm or less in a particle size accumulation curve. A powder binder having a particle size distribution as follows.

A method of manufacturing a glass chopped strand mat in which the glass chopped strands are bonded to each other by spraying and heating a binder on a sheet-like deposit of glass chopped strands and then cooling and solidifying the softened binder. The agent is a powder binder having a particle size distribution such that D ₅₀ (average particle size) of the effective particle size in the particle size accumulation curve is 275 μm or more and 325 μm or less, D ₁₀ is 240 μm or more, and D ₉₀ is 390 μm or less. Is the following configuration. That is, in the present invention, after spraying a binder (also referred to as a secondary binder or a secondary binder) from above the glass chopped strands that have been cut into a predetermined length, stacked on the transport net of the transport conveyor, and deposited evenly and randomly. In this manufacturing method, the binder is heated to the softening temperature, softened, blended with the glass chopped strands, and further cooled and solidified to form the matted glass chopped strands in a bonded state. is there. When the particle size distribution of the above-mentioned binder used in the glass chopped strand mat manufacturing method is measured by a particle size distribution measuring device, the effective particle size D ₅₀ (average particle size) in the particle size accumulation curve is 275 μm or more. And 325 μm or less, D ₁₀ is 240 μm or more, and D ₉₀ is 390 μm or less.

  When the binder having the configuration of the present invention is sprayed from above where the glass chopped strands are deposited and laminated, the binder is evenly sprayed at appropriate positions of the deposited glass chopped strands, and from the gaps of the deposited glass chopped strands. The fall of is also suppressed. For this reason, when the glass chopped strands are bonded together by cooling and solidifying the softened binder in this state, the bonding points of the glass chopped strands constituting the obtained mat are evenly distributed, and the tensile strength is locally Thus, the glass chopped strand mat has a stable tensile strength with no bias.

When a powdery binder is dispersed on a glass chopped strand (sheet-like deposit) deposited in a sheet form, D ₅₀ (average particle diameter) which is an effective particle diameter in a particle size accumulation curve of the binder ) Is less than 275 μm, the particle size of the binder becomes too fine, and the rate at which each powder is fixed on the appropriate bonding point where the glass chopped strands are bonded to each other is reduced, contributing to adhesion. Since the amount of the binder tends to decrease, adhesion between the glass chopped strands by the binder is weakened, and the glass chopped strand mat may be easily broken, which is not preferable. Moreover, when the particle size of a binder becomes small, since the fluidity | liquidity characteristic in the hopper used when spraying falls, it is unpreferable. In addition, it may occur that the binder is not evenly sprayed due to the influence of the manufacturing environment such as the convection of the atmosphere in the process and the distance from the spraying position to the deposit, which is also preferable from this viewpoint. Absent.

Also, if the D ₅₀ in the particle size accumulation curve of the binder _(average particle diameter) exceeds 325Myuemu, fewer optimal adhesion points that bind the glass chopped strand between each other when using the same amount of binder Too much. When a mat is produced using a binder in such a state, dropout of the glass chopped strands in the production process, that is, strand drop increases, the tensile strength of the entire glass chopped strand mat becomes weak, and there is a possibility of leading to breakage or tearing. is there. Dropping off of glass chopped strands means that glass chopped strands that are not joined to each other and that are not involved as mat forming members are generated. Further, in order to increase the adhesion point in order to compensate for the decrease in the adhesion point, it is necessary to increase the spray amount, which is not preferable because it hinders efficient production. Also, if the particle size of the binder becomes too large, it will be difficult to spread the binder evenly to the lowest layer of the glass chopped strand in the deposited state, which will be one of the causes of increased strand fall and the equality of the binder. This is not preferable because it will hinder proper spraying.

When the D ₁₀ in the particle size accumulation curve of the binder is less than 240μm also too fine particle size of the binder, with the rate of fixing on position of the bonding point glass chopped strands are bonded to each other is low, for example Even if the bonding agent adheres to the adhesion point, it is not preferable because an adhesion amount suitable for adhering the glass chopped strands to each other cannot be achieved.

When D ₁₀ in the particle size accumulation curve of the binder exceeds 390 μm, the glass chopped strands are combined when the same amount of binder is used as in the case of D ₅₀ (average particle diameter) exceeding 325 μm. There are too few optimal points of adhesion to bond together. When a mat is produced using a binder in such a state, dropout of the glass chopped strands in the production process, that is, strand drop increases, the tensile strength of the entire glass chopped strand mat becomes weak, and there is a possibility of leading to breakage or tearing. This is not preferable. To increase the number of adhesion points, excessive spraying more than necessary is required, and it is not economical.

  When the binder is not sufficiently applied to the bonding points that contribute to the bonding as described above, the part where the amount of the binder adhering in addition to the bonding point becomes harder than other parts, and the produced glass chopped The flexibility of the strand mat is reduced. When a glass chopped strand mat in such a state is molded as a roof liner for an automobile, for example, if this hard part is placed in an opening of a shade or the like and a corner of a deep drawing, a skin wrinkle called sink will occur. Defects may occur. Further, if the amount of the binder is reduced in order to avoid the occurrence of sink marks, the tensile strength of the portion having a small basis weight of the chopped strand mat becomes weak. For this reason, in order to apply an adhesive such as phenol, melamine, or isocyanate to a glass chopped strand mat, when the mat is pulled out from the mat wound body, or in the process of molding the roof liner, the skin (inside the automobile), the glass chopped A mat from a resin-impregnated chopped strand mat roll wound up by a glass chopped strand mat coated with an adhesive in a process of stacking a strand mat, a foamed resin sheet, a glass chopped strand mat, and a protective sheet (on the ceiling of an automobile) in this order. When sequentially pulling out the glass, there arises a problem that the mat is broken, that is, torn off from the thin portion of the glass chopped strand mat.

In order to measure each value of D ₅₀ (average particle size), D ₁₀ , and D ₉₀ of the effective particle size in the particle size accumulation curve, first, a representative representative of the binder is sampled by a reduction method or the like, For example, the particle size measurement value may be specified by measuring the particle size with a laser particle size measuring device defined in JIS R1629 (1997). Specifically, for example, it may be measured with a precision of up to one decimal place in μm units using a particle size precision measuring device such as Microtrac manufactured by Nikkiso Co., Ltd., SALD2000J manufactured by Shimadzu Corporation.

  In order to realize the particle size distribution configuration of the binder of the present invention, for example, the binder obtained by chemically adjusting in advance is any one of mechanical pulverizers such as a ball mill, a medium stirring mill, and an airflow pulverizer. Can be used to grind. A ball mill is a processing device that uses ceramics or natural ore as a driving body called a ball, and repeatedly crushes and crushes the object to be crushed by repeatedly colliding the driving body with the surface of the object to be crushed. is there. As this ball mill, a rolling ball mill (a ball mill in a narrow sense) that performs grinding in the most general cylindrical or conical containers, a vibration mill that performs fine grinding by applying fine vibration to the ball, A medium planetary mill or the like that is accelerated to improve the grinding efficiency may be used. A medium agitation mill is a mechanism that makes a medium collide with an object to be crushed like a ball mill. This is a pulverizer capable of pulverization. As the medium agitating mill, generally, an aniler mill type, a tower mill type, a sand grinder mill type, an attritor mill type or the like can be used. Even when these devices are used, it is possible to apply the present invention by taking the same measures as in the case of the above-described ball mill. Furthermore, the airflow type pulverizer is a pulverization apparatus that employs a method of pulverizing by forcibly colliding the object to be pulverized by a high-speed jet airflow or the like, and is suitable for adjusting powder having a uniform particle size. In particular, when the apparatus is used, a desired pulverization environment can be realized by setting the atmosphere of the jet stream itself to be adjusted so as to be maintained in a high humidity environment.

  As the binder according to the present invention, any binder can be used as long as it can be softened at 50 to 300 ° C. and can be sufficiently cooled and solidified. For example, a polyester resin, a polyethylene resin, a polyvinyl acetate resin, or a mixture thereof. A bisphenol unsaturated polyester resin or the like may be used.

  The glass chopped strand mat according to the present invention can be easily cooled on the surface of the glass chopped strand by heating if the binder contains a bisphenol unsaturated polyester resin in addition to the above. To solidify the glass chopped strands with sufficient adhesive strength. For this reason, a glass chopped strand mat having a superior quality in terms of flexibility, such as mechanical strength resulting from the bonding performance after becoming a mat and ease of handling of the mat, is preferable.

  That the binder contains a bisphenol-based unsaturated polyester resin means that, for example, an unsaturated polyester resin having a bisphenol group in the skeleton is used as the binder.

  In addition to the above, the method for producing the glass chopped strand mat of the present invention is economically high in production efficiency, as long as the binder is obtained through a sieving step after a ball milling step, It is preferable because a binder having a desired particle size can be obtained.

  The binder is obtained through a sieving step after the ball milling step. The binder obtained by chemical synthesis is pulverized with a ball mill and then classified by sieving to adjust the particle size. It means that it was obtained.

The glass chopped strand mat of the present invention is manufactured by the method for manufacturing a glass chopped strand mat of the present invention, and is characterized by being in the range of 50 g / m ² or more and 200 g / m ² or less.

The glass chopped strand of the present invention is a glass chopped strand mat in which the glass chopped strands are bonded to each other by cooling and solidifying the softened binder after spraying and heating the binder on the sheet-like deposit of the glass chopped strands. In the production method, the binder has an effective particle size D ₅₀ (average particle size) of 275 μm or more and 325 μm or less, D ₁₀ of 240 μm or more, and D ₉₀ of 390 μm or less in the particle size accumulation curve. It is manufactured by the manufacturing method of the glass chopped strand mat characterized by the above-mentioned. The obtained glass chopped strand mat has a basis weight in the range of 50 g / m ² or more and 200 g / m ² or less.

If the basis weight of the glass chopped strand mat is less than 50 g / m ² , the number of adhesion points decreases, and a case where sufficient tensile strength cannot be obtained tends to occur. If the basis weight of the glass chopped strand mat exceeds 200 g / m ² , the weight of the mat becomes heavy and the flexibility of the mat may be lost.

  The roof liner of the present invention can be used as a molding ceiling for various automobiles if the glass chopped strand mat is bonded to either one of the front and back surfaces of the foamed resin sheet, and deep drawing molding is also easy. is there.

  The roof liner of the present invention is a roof liner formed by adhering to at least one side of the front surface or the back surface of the foamed resin sheet with an adhesive of either phenol, melamine, or isocyanate in addition to the above. When the glass chopped strand mat is employed only on one side of the sheet material using the foamed resin, it is not particularly limited to use reinforcing materials of different materials on the other side.

In the roof liner of the present invention, for example, a glass chopped strand mat coated with an adhesive is composed of an outer skin (automotive interior side), a glass chopped strand mat, a foamed resin sheet, a glass chopped strand mat, and a protective sheet (automotive ceiling side). What is necessary is just to superimpose and manufacture in order.

(1) As described above, in the method for producing a glass chopped strand mat of the present invention, the glass chopped strand sheet-like deposit is heated by spraying the binder, and then the softened binder is cooled and solidified. A method for producing a glass chopped strand mat for bonding chopped strands, wherein the binder has an effective particle size D ₅₀ (average particle size) of 275 μm or more, 325 μm or less, and D ₁₀ of 240 μm in a particle size accumulation curve. above, D ₉₀ is for a powder binder having a particle size distribution comprising less 390 [mu] m, evenly adheres evenly to the sheet-like deposits glass chopped strands. For this reason, it is possible to obtain an adhesion point necessary for bonding of the glass chopped strands, and as a result, it is possible to prevent unevenness in the tensile strength, which is an index of the mechanical strength of the glass chopped strand mat, from occurring due to the site. . And since it has such an equivalent mechanical strength, when pulling out the glass chopped strand mat from the mat wound body and unwinding it, the operation can be performed smoothly, and problems such as breakage of the glass chopped strand mat, etc. It is possible to suppress the occurrence of this.

  (2) In the method for producing a glass chopped strand mat of the present invention, if the binder contains a bisphenol-based unsaturated polyester resin, the binder is easily softened on the sheet-like deposit of the glass chopped strand, Since the glass chopped strands are well-familiar and can be easily solidified so that the glass chopped strands are firmly bonded to each other, stable production of the glass chopped strand mat can be performed.

  (3) In the glass chopped strand mat of the present invention, since the binder is obtained through a sieving step after a ball milling step, it is easy to adjust the particle size to an appropriate range, and the shape is moderate. It is easy to adhere to the proper adhesion point of the glass chopped strand. Further, since the surface area of the pulverized product is large, the heat absorption is fast, the softening during heating is smoothly performed, and the production efficiency of the glass chopped strand mat can be improved.

(4) Moreover, the glass chopped strand mat of the present invention is manufactured by the method for manufacturing the glass chopped strand mat of the present invention, and the basis weight is within the range of 50 g / m ² to 200 g / m ^2. This is a mat-like structural reinforcing material with a high degree of flexibility, and when used in a roof liner or the like for an automobile having a complicated shape such as a deep drawing part, it is reliably reinforced by reducing the occurrence of molding defects such as sink marks. It will be possible.

  (5) Since the glass chopped strand mat of the present invention is bonded to either one of the front and back surfaces of the foamed resin sheet, the roof liner of the present invention can be applied to various automobile shapes and is lightweight. In addition, it has sufficient strength and exhibits many performances such as higher rigidity, heat insulation and sound insulation.

Explanatory drawing which shows the manufacturing process of the glass chopped strand mat of this invention. Partial expansion explanatory drawing of the glass chopped strand mat of this invention.

  Hereinafter, based on an Example and a comparative example, it demonstrates in detail about the manufacturing method of the glass chopped strand mat of this invention, the glass chopped strand mat, and the roof liner using the glass chopped strand mat of this invention, referring FIG. 1, FIG. explain.

  First, the manufacturing method of the glass chopped strand mat of this invention is demonstrated according to process order.

  A glass raw material prepared in advance is uniformly melted in a glass melting furnace (not shown), and the obtained molten glass of the E glass material in a homogeneous state is led to a platinum bushing (not shown). Next, a glass filament having a diameter of 11.6 μm is continuously drawn from a platinum bushing having 1200 nozzles and molded. A sizing agent is applied to the surface of the drawn glass filament. The components of the sizing agent are 4% by mass of a polyvinyl acetate emulsion in terms of solid content of 100% by mass, 0.3% by mass of γ-methacryloxypropyltrimethoxysilane, 0.5% by mass of quaternary ammonium salt, ions The exchanged water is adjusted to 95.2% by mass. Here, this sizing agent is applied so that the adhesion rate to the surface of the glass filament is 0.4 mass%. 1200 glass filaments coated with a sizing agent are split and bundled by a carbon shoe. And it becomes the 18 glass strands 10 which consist of 68 glass filaments, and is wound up by the bobbin, and the glass cake 5 shown in FIG. 1 is obtained. Thereafter, the glass cake 5 is dried for a predetermined time to evaporate water, and the sizing agent is fixed on the surface of the glass filament.

  As shown in FIG. 1, each cutting machine 12 of the glass fiber mat manufacturing apparatus 50 is disposed on the ceiling portion of the chamber 11, and is composed of a pair of cutter rolls 12a and rubber rolls 12b that rotate in opposite directions. . The glass strands 10 continuously unwound from the inner layer of the glass cake 5 after the drying process are sequentially fed between the cutter rolls 12a and the rubber rolls 12b of the respective cutting machines 12, and have a length of 50 mm. Cut continuously into dimensions.

The glass chopped strands 10a cut to a length of 50 mm are stacked so as to be uniformly dispersed on the first conveyor 13 disposed at the bottom of the chamber 11, and are successively deposited in a sheet form. In such a state, it is conveyed out of the chamber 11 by the first conveyor 13. Glass chopped strand 10a that is deposited and then is transferred to the second conveyor 14 of the next, on a sheet-like deposits 10b of glass chopped strands 10a moving on the second conveyor 14, average particle size (D ₅₀₎ Is 308 μm, D ₁₀ is 254 μm, and D ₉₀ is 386 μm. The powder binder P made of a bisphenol-based unsaturated polyester resin is adjusted to a uniform state and used as a binder for the chopped strands 10a. 11% by mass), and is spread evenly by the spreader 15. For the measurement of the average particle diameter and the like of this powder binder, SALD2000J manufactured by Shimadzu Corporation was used. Incidentally, the powder binder P made of the bisphenol-based unsaturated polyester resin is dried after chemically synthesized, and then pulverized for a predetermined time using a ball mill having alumina balls. It was obtained by adjusting the diameter.

Then, the sheet-like deposit 10b of the glass chopped strands 10a uniformly distributed on the belt conveyor 14 and the powder binder P distributed from above are in close contact with each other from the second conveyor 14 to the third. Transferred onto the conveyor 16. A heating furnace 17 is disposed in the middle of the third conveyor 16, and the sheet-like deposit 10 b on which the powder binder P is dispersed moves into the heating furnace 17 and is heated at a predetermined temperature. It will be. Subsequently, the powdery binder P spread on the surface of the glass chopped strand 10a is softened and melted to move the sheet-like deposit 10b to the outside of the heating furnace 17, and the water-cooled press roll 18a of the cooling and rolling mill 18 is moved. Cool and press through 18b. Incidentally, as shown in FIG. 1, the cooling and rolling mill 18 includes a water-cooled press roll 18b that rotates in the feeding direction disposed below the mat, and a water-cooled press that is disposed above the mat that rotates in the opposite direction. This is an apparatus for inserting and rolling the sheet-like deposit 10b in which the powder binder P dispersed on the surface of the glass chopped strand 10a is softened and melted in the gap with the press roll 18a in the feeding direction. . By performing this cold rolling operation, the melted powder binder P is solidified, and then wound up by the winder 21 to finally rotate the glass chopped strand mat 19 (weight per unit area: 107 g / m ² ). A roll 20 is obtained.

  Samples having a width of 150 mm and a length of 300 mm were collected in the width direction from the glass chopped strand mat 19 thus obtained, and the tensile strength was measured according to JIS R3420 (2006). Measurement was performed at a tensile speed of 200 mm / min. The measurement results are shown in Table 1 together with average values and standard deviation values.

  Further, in the glass chopped strand mat 19 obtained by the above process, as shown in FIG. 2 as a model, the dispersion state of the glass chopped strand 10a and the distribution state of the adhesion points 2 obtained by the powder binder are shown as models. Adhesive points 2 that are evenly distributed on the surface of the chopped strand 10a can be obtained, and the bias of the adhesive points 2 is not recognized.

  The performance of a molded ceiling material for automobiles manufactured using the glass chopped strand mat 19 thus obtained, that is, a roof liner, was investigated. The contents will be described below.

  First, as shown in Table 1, No. of a trial manufacture number which is an example of the present invention. 1 to No. No. 5 and a comparative trial production number No. 101 and no. A total of 7 types of samples were prepared. That is, after impregnating a glass chopped strand mat 19 having a predetermined dimension of an E glass material, which is a strand count of Table 1, and adjusted to have a predetermined mat basis weight, with an isocyanate-based adhesive, The glass chopped strand mat 19, the foamed polyurethane sheet, another glass chopped strand mat 19 and a protective sheet (on the ceiling side of the automobile) are stacked in this order. Next, this laminate was put into a press die having the shape of a ceiling of an automobile, and in that state, press molding was performed to obtain a predetermined shape, and then the periphery thereof was trimmed and arranged.

  The strand count (tex) in the glass chopped strand mat 19 was measured by incinerating the chopped strand mat 19 at 620 ° C. for 30 minutes, and then extracting 50 strands constituting the chopped strand mat 19 and measuring the average length L ( mm), 50 total masses W (g) are measured using a scale having a sensitivity of 0.1 mg or less, and can be calculated by the equation shown in Equation 1. Since this equation represents the weight of a strand length of 1000 m, the unit is converted from millimeters (mm) to meters (m).

   Each sample prepared by the above procedure was investigated by the following evaluation method.

  With respect to the adhesion amount of the binder of the glass chopped strand mat, the ignition loss of the cake used for the production of the glass chopped strand (0. 0) from the ignition loss of the glass chopped strand mat measured by the method described in JIS R3420 (2006). 4% by mass) was subtracted.

  The evaluation of the roof roofer for automobiles of the present invention was carried out by an expert who inspected the quantity of sink marks on the skin side of 1000 roof roofers for automobiles by visual observation. The above results are shown in Table 1.

As is clear from Table 1, sample No. 1 is a sample having a strand count of 19 tex, a mat basis weight of 107 g / m ² , and a binder adhesion amount of 10.5%. The particle size of the powder binder is D ₅₀ = 308 μm, D ₁₀ = 254 μm, D ₉₀ = The glass chopped strand mat has a tensile strength of 230 N with an average value of 230 N and a standard deviation of 42 N, and has a sufficiently high tensile strength, and its variation is small. It is a value. For this reason, when the glass chopped strand mat is unwound and pulled out from the mat wound body, the glass chopped strand mat is flexible and can be pulled out smoothly without tearing. Defects due to defects were 0%.

Sample No. No. 2 is a sample having a strand count of 19 tex, a mat basis weight of 106 g / m ² , and a binder adhesion amount of 10.5%. The particle size of the powder binder is D ₅₀ = 308 μm, D ₁₀ = 254 μm, D ₉₀ = It is manufactured using 386 μm. The average strength of the obtained glass chopped strand mat was 225N and the standard deviation was 44N. The glass chopped strand mat is wound around a mat roll, and then the resin-impregnated chopped strand mat is removed when the mat is unwound from the glass chopped strand mat roll impregnated with resin in the automobile roofer manufacturing process. There was no breakage, and no defects due to sink defects were found in Sample No. Similar to 1, it was not recognized at all.

Furthermore, sample no. 3 to sample no. For sample No. 5, sample no. 3 uses a strand count of 19 tex, a mat basis weight of 106 g / m ² , a powder binder adhering amount of 11.0%, and a binder particle size of D ₅₀ = 290 μm, D ₁₀ = 245 μm, D ₉₀ = 370 μm Sample No. manufactured as sample No. 4 using a strand count of 20 tex, a mat basis weight of 106 g / m ² , a binder adhesion amount of 11.0%, a binder particle size of D ₅₀ = 295 μm, D ₁₀ = 245 μm, D ₉₀ = 375 μm The manufactured sample, Sample No. 5 using a strand count of 20 tex, a mat weight of 107 g / m ² , a binder adhesion amount of 12.0%, a binder particle size of D ₅₀ = 295 μm, D ₁₀ = 240 μm, D ₉₀ = 375 μm This is a manufactured sample. These sample Nos. 3 to sample no. For sample No. 5, no defect due to sink marks was observed, and the mat was not torn off when the glass chopped strand mat was unwound from the mat roll and pulled out. The tensile strength of the glass chopped strand mat is the same as that of Sample No. 3 has an average value of 233N and a standard deviation of 43N. 4 has an average value of 240 N and a standard deviation of 45 N, sample No. No. 5 had an average value of 250 N and a standard deviation of 48 N, all of which had no problem with respect to tensile strength.

In summary, sample No. 1 to sample no. For 5 samples, above binders granularity _{D 50} of 290μm, 308μm or _{less, D 10} is more than 240 .mu.m, 254 micrometers or _{less, D 90} is more than 370 .mu.m, it was below 386μm. In this way, a binder having a particle size within the range satisfying the requirements of the present invention is used so that the binder adhesion amount is 10.5% or more and 12.0% or less, and the mat basis weight is 106 g / m ² or more and 107 g. For glass chopped strand mats of / m ² or less, the glass chopped strand mats of the examples of the present invention have an average tensile strength in the range of 225 N or more and 250 N or less, and the standard deviation is 42 N or more and 48 N or less. It was found to have a sufficiently high and stable tensile strength.

On the other hand, sample No. which is a comparative example. No. 101 has a strand count of 20 tex, a mat basis weight of 107 g / m ² , a binder adhesion amount of 12.0%, and a powder binder particle size of D ₅₀ = 183 μm, D ₁₀ = 128 μm, D ₉₀ = 385 μm. state is a sample prepared using, for D ₁₀ and D ₉₀ of which is outside the scope of the claims of this patent, the binder is not evenly distributed bonding points, attached to the strands of the non-adhesive points It becomes. For this reason, since the glass chopped strand mat has a highly rigid portion, the average value of the tensile strength is 290N, the standard deviation is 120N, and the grade is highly varied. Since there was a part with very high strength, flexibility was lost and the incidence of sink defects was as high as 20%.

Sample No. which is a comparative example. No. 102 has a strand count of 19 tex, a mat basis weight of 106 g / m ² , a binder adhesion amount of 10.0%, and a powder binder particle size of D ₅₀ = 350 μm, D ₁₀ = 242 μm, D ₉₀ = 425 μm. Samples manufactured using, but because D ₅₀ and D ₉₀ are outside the scope of the claims of this patent, the binder is not evenly dispersed in the glass chopped strand mat, and there are few adhesion points, so it is partially There was a weak portion, and tearing occurred when the mat was unwound from the glass chopped strand mat roll, that is, the mat wound body.

  As described above, the method for producing a glass chopped strand mat of the present invention can efficiently produce the glass chopped strand mat of the present invention having stable quality. Moreover, it became clear that the roof liner for automobiles of the present invention can be reduced in weight without causing a problem with strength, and has an excellent quality with no occurrence of sink defects in terms of appearance quality.

  The method for producing a glass chopped strand mat of the present invention is preferably used as a method for producing a glass chopped strand mat used in an automobile roof liner, but in addition, it is a constituent material for various precision instruments such as electronic components. It can also be applied to the manufacture of chopped strand mats used for various applications such as building / civil engineering repair materials, housing components, and various components for FRP applications.

2 Bonding point 5 Glass cake 10 Glass strand 10a Glass chopped strand 10b Sheet deposit 11 Chamber 12 Cutting device 12a Cutter roll 12b Rubber roll 13 First transport conveyor 14 Second transport conveyor 15 Spreader 16 Third transport conveyor 17 Heating furnace 18 Cooling and rolling mills 18a and 18b Cooling press roll 19 Glass chopped strand mat 20 Glass chopped strand mat roll (mat wound body)
21 Winder 50 Glass fiber mat manufacturing apparatus P Powder binder L Average length of glass chopped strands W Total mass of 50 glass chopped strands

Claims (3)

After heating by spraying a binder into a sheet deposit glass chopped strands, it is prepared by coupling the glass chopped strand together by cooling and solidifying the softened binder, a basis weight of 50 g / m ² or more , 200 g / m ² or less of a glass chopped strand mat manufacturing method,
The binder has an effective particle size D ₅₀ (average particle size) of 275 μm or more and 325 μm or less, a D ₁₀ of 240 μm or more, and a D ₉₀ of 390 μm or less in a particle size accumulation curve. A method for producing a glass chopped strand mat, wherein the binder is obtained through a sieving step after a pulverizing step with a mechanical pulverizer.   The method for producing a glass chopped strand mat according to claim 1, wherein the mechanical pulverizer is a ball mill, a medium agitating mill, or an airflow pulverizer. The method for producing a glass chopped strand mat according to claim 1 or 2, wherein the binder contains a bisphenol unsaturated polyester resin.