JPS6035944B2 - Glass fiber reinforced polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to glass fiber reinforced polyester resin compositions passed through injection molding materials.

More specifically, the present invention relates to a glass fiber-reinforced polyester resin composition which is made by reinforcing a linear polyester such as polybutylene terephthalate with glass fibers and has excellent mechanical strength and improved mold shrinkage properties. It is something. Conventionally, linear polyester resins reinforced with glass fibers have a
It is known to have significantly improved mechanical properties and heat resistance.

For example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, etc. are widely used. Among them, polybutylene terephthalate has a low crystallization temperature, so it is possible to obtain homogeneous molded products that are sufficiently crystallized at the mold temperature used for molding ordinary thermoplastic resins, and it also has excellent mechanical strength. It is being used for mechanical parts, etc. However, when injection molding is performed using glass fiber-reinforced polybutylene terephthalate resins currently on the market, the glass fibers tend to become knotted in the flow direction of the resin in the molded product.

Therefore, the molding shrinkage is highly variable, and when the above composition is applied to molding applications such as large molded products and box-shaped molded products, the molded product is likely to undergo IJ deformation, reducing the commercial value of the molded product. cause it to happen. As a method to improve the warp deformation of this molded product, it is possible to fill it with shaped glass beads or glass fibers with a short average length (approximately 50 to 70 peaks) and a small ratio of average length to average diameter. However, these have extremely low mechanical strength and are unsuitable for use in large molded products.

In addition, mechanical strength was improved by adding and mixing polybutyresoterephthalate with long glass fibers several ribs long and a polyfunctional compound (Japanese Patent Publication No. 51-770
2), or it is known that mechanical strength and formability can be improved by adding and mixing clay poppy or acid salts (Japanese Patent Application Laid-Open No. 48-84138). However, it was still insufficient in terms of eliminating warp deformation of molded products.

As described above, it has been extremely difficult to eliminate warping of molded products and provide them with practical mechanical strength. In view of the current situation, the present inventors have conducted intensive studies to obtain a glass fiber-reinforced polyester resin composition that improves these drawbacks, and as a result, they have found that glass fibers of specific dimensions and a polyfunctional compound are blended into polybutylene terephthalate. The present invention was achieved by discovering that a molded article suitable for practical use and having excellent mechanical strength and moldability can be obtained by using the method.

That is, the present invention provides a polyester resin composition containing wind polybutylene terephthalate, 'B' glass fiber, and a polyfunctional compound selected from [C] polyepoxy compounds, polyisocyanate compounds, epoxysilane compounds, or aminosilane compounds. - Contains fibers with a length of 300 A or more at 2% by weight or less as a component,
The present invention also provides a glass fiber-reinforced polyester resin composition characterized in that glass fibers having a ratio of average length to average direct diameter of 10 to 22 are used.

The present invention will be explained in detail below.

Polybutylene terephthalate, component (1) of the composition of the present invention, is obtained by polycondensation of 1,4-butanediol and terephthalic acid or a dialkyl ester of terephthalic acid.

Further, a copolymer mainly composed of polybutylene terephthalate in which 20 mol% or less of the alcohol component and brewing component constituting the polyester is replaced with other copolymerizable components may also be used. In this case, the copolymer components include ethylene glycol, diethylene glycol, 2,2-bis(4-
A diol such as 3-oxyethoxy(3,5-dibromphenyl)propane, isophthalic acid,
Mention may be made of dicarboxylic acids such as adipic acid.
Also, the intrinsic viscosity of the polybutylene terephthalate used (
3000 using a mixed solvent of phenol:tetrachloroethane=1:1) is preferably 0.8 or more. If the intrinsic viscosity is less than 0.8, the crystallization rate will be extremely high, so even if glass fibers having the above-mentioned specific dimensions are used, the deformation of the molded article cannot be sufficiently improved. The glass fiber, which is the Tsukuda component of the composition of the present invention, must have dimensions and particle size distribution within a specific range.

That is, the ratio of the average length L to the average diameter D of the glass fibers (
L/D) is required to be 10 to 22, and it is necessary that the length of 300 peaks or more is 2% by weight or less based on the total glass fibers. If the ratio of the average length to the average diameter is less than 10, the mechanical strength will deteriorate, while if it exceeds 22, warp deformation of the molded product will suddenly become significant, which is not preferable. Preferably, L/D is selected from the range of 13-20. Further, if the glass fibers having a length of 300 or more strands exceeds 2% by weight based on the total glass fibers, the warp deformation becomes significant as well, which is not preferable. It is essential that the glass fibers used in the present invention have a ratio of average length to average diameter of 10 to 22, especially those in which most of the glass fibers are between 10 and 22. preferable. In other words, long fibers with a value of 300 or more are 1
It is preferably 5% by weight or less. On the other hand, if too short glass fibers, for example, fibers with 30 threads or less, are present in large quantities, the strength will decrease, so it is better to reduce the number of glass fibers as much as possible.

Further, the diameter of the glass fiber used is usually 6 to 15 mm. The amount of the glass fiber used is desirably 10 to 6% by weight, particularly 20 to 5% by weight, based on the total amount of the composition.

If it is less than 1% by weight, the strength improving effect is insufficient, and if it is more than 6% by weight, it becomes brittle, which is not preferable.

The polyfunctional compound which is the {C} component of the composition of the present invention includes a polyepoxy compound having two or more epipoxy groups;
Polyisocyanate compound having two or more isocyanate groups, general formula Rn-Six4-n (R is an organic group having an amino group or an epoxy group, ×
is an alkoxy group or a halogen atom, or n is 0 to
Shows the number 4.

) and the like. Specifically, bisphenol A type epoxy resin, halogenated bisphenol A type epoxy resin, tetrahydroxyphenylmethane type epoxy resin, novolac type epoxy resin, vinylcyclohexene dioxide, dicyclobentadiene dioxide, triepoxyf.

Polyepoxy compounds such as lopylisocyanurate, N,N-diglycidyl-toluidine, etc.: 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, polyphenyl isocyanate Polyisocyanate compounds such as silane compounds such as y-aminopropyltriethoxysilane, N-3-aminoethyl-y-aminopropyltrimethoxysilane, and y-glycidoxypropyltriethoxysilane, y-glycidoxypropyltriethoxysilane; Epoxysilane compounds such as -glycidoxypropyltrimethoxysilane and 8-(3,4-epoxycyclohexyl)ethyltrimethoxysilane can be used. The amount of the polyfunctional compound added is arbitrarily selected from the range of 0.01 to 1% by weight, preferably 0.1 to 5% by weight, based on the total amount of the resin composition, but if the amount added is 0.01% by weight, preferably 0.1 to 5% by weight. If the amount is less than 1% by weight, no strength improvement effect can be obtained, and if it is more than 1% by weight, the properties of the polyester resin itself are inhibited and the moldability is reduced, which is not preferable.

When one or more of these polynephric compounds are contained in the composition, the adhesive strength between the resins and between the resin and the glass fibers is improved, resulting in a glass fiber reinforcement with extremely excellent mechanical strength. A polyester resin composition can be obtained.

In the present invention, the mixing of the resin, the 'B' glass fiber, and the [C] polyfunctional compound is carried out, for example, by the following method.

m ■Polyester resin, {B}glass fiber, and ■
A method of mixing polyfunctional compounds by dry blending and using the same as a molding material, '21 A method of melting and mixing the above-mentioned dry blend in an extruder, cutting it into pellet shapes, and using it as a molding material, {3' style polyester A dry blend of a resin, a chopped strand of glass fiber with an average length of several ribs, and a polyfunctional compound is pulverized so that the chopped strand of glass fiber has physical properties within the scope of the present invention. A method in which the material is melt-kneaded in an extruder that applies shear stress, such as a two-mice extruder, and then cut into pellets and used as a molding material.

It goes without saying that the present composition may also contain retardants, pigments, lubricants, stabilizers, ultraviolet absorbers, and other additives.

The composition of the present invention thus obtained can be easily injection molded without using a high-temperature mold or heat-treating the molded product, and the molded product has excellent mechanical strength and Most molded products are subject to warping and deformation.

Therefore, it can be an extremely advantageous injection molding material not only for ordinary molded products, but also for applications such as particularly large molded products and box-shaped molded products. The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

Example 1 Chopped sland glass fiber (manufactured by Asahi Fiberglass Co., Ltd.: 3 ribs in length) was ball milled, crushed and divided into L.
/D=12.0, a length of 300 French or more, and a glass fiber content of 3% by weight was produced.

59.6% by weight of polybutylene terephthalate (manufactured by Mitsubishi Chemical Industries, Ltd. 5008) having an intrinsic viscosity of 0.85, 59.6% by weight of the above-mentioned glass fiber 4, and y-glycidoxypropyltrimethoxysilane (A-manufactured by Munion Carbide). 187) 0.
After thoroughly mixing 4% by weight of the three components in a blender, this was mixed at 40% by weight.
Supply to J pent type extruder, cylinder temperature 250
A polybutylene terephthalate resin composition containing glass fibers was obtained by beletizing with CO. Using this composition as a molding material, an injection molding machine (manufactured by Japan Steel Works) was used under molding conditions of a cylinder temperature of 25,000 degrees and a mold temperature of 80 degrees.
0 side diameter x l. 6 side thickness disc and ASTM-D-25
An isod impact test piece according to No. 6 was prepared. As a measure of the degree of warp deformation when the molding material is made into a molded product, the warp (saddle-shaped deformation) of the disk was measured. The degree of warpage was expressed as the sum of the height of the highest point of the peripheral portion when the disk was placed on a flat surface and the height of the opposing peripheral portion across the center. The warp deformation of the molded product is 0.
It had 3 ribs, and was so minute that it could hardly be noticed by normal visual observation. Further, the Izod impact strength was 3.5k9-ka/skin. Examples 2, 3 and Comparative Examples 1, 2, 3 Various glass fibers as shown in Table 1 were produced in the same manner as in Example 1.

A disk was molded in exactly the same manner as in Example 1, except that the type of glass fiber was changed, and warp and Izod impact tests were conducted. The results are shown in Table 1. Note that the results of Example 1 are also listed. Furthermore, in Table 1, y-glycidoxypropyltrimethoxysilane is abbreviated as epoxysilane. The results of Examples 1, 2, and 3 and Comparative Examples 1 and 2 are illustrated in FIG.

In the figure, the machine axis indicates the ratio of the average length L to the average diameter D of the glass fibers, and the vertical axis indicates the Izod impact strength (k9 one skin/skin) or warp deformation (ribs). Further, curve 1 shows the relationship between L/D and Izod impact strength, and line 2 shows the relationship between L/D and warp deformation. From Figure 1, L/D=5~2
While the Izod impact strength changes gradually in the range of 5, surprisingly the warpage of the disc is almost constant in the range of L/DS 20, but changes rapidly in the range of L/D = 20 to 25. It can be seen that when glass fibers having L/D in the range of 10 to 22 are used, a glass fiber-containing polybutylene terephthalate resin without deformation of the molded article and having good mechanical properties can be obtained. Example 4 Polybutylene terephthalate with an intrinsic viscosity of 0.85 59.
4% by weight, 4% by weight of milled fiber (prototype manufactured by Asahi Fiberglass Co., Ltd.; L/D=15, glass fiber content 1% by weight with a length of 300 French or more), and 1% by weight of tris(epoxypropyl) isocyanurate. were mixed and molded in the same manner as in Example 1, and the warpage and Izod impact strength of the disc were measured.

The results are shown in Table 1. In Table 1, tris(epoxypropyl)isocyanurate is abbreviated as polyepoxide 1. Example 5 A mixture of Q-aminopropyltriethoxysilane and bisphenol A type epoxy resin was used instead of tris(epoxypropyl)isocyanurate as a polyfunctional compound, and the amount of the component A disk was molded in exactly the same manner as in Example 4, except that the warpage and Izod impact strength were measured.

The results are shown in Table 1. In Table 1, Q-aminopropyltriethoxysilane is used as aminosilane, and bisphenol A-type epoxy resin is used as polyepoxide A.
It was abbreviated as. Example 6 Example 6 except that polymethylene polyphenylisocyanate was used instead of tris(epoxypropyl) isocyanurate as the polyfunctional compound, and the amount of the component was changed. A disk was molded in exactly the same manner as in 4, and the warpage and Izod impact strength were measured.

The results are shown in Table 1. In addition, in Table 1, polymethylene polyphenylysocyanate is abbreviated as polyisocyanate. Comparative Example 4 A disk was molded in exactly the same manner as in Example 2, except that no polyfunctional compound was added, and the warpage and Izod impact strength were measured.

The results are shown in Table 1. Comparative Example 5 97% by weight of polybutylene terephthalate with an intrinsic viscosity of 0.85, chopped strand glass fiber (manufactured by Asahi Fiberglass Co., Ltd.: L/D = 23-27, fiber content of 50-65% by weight with a length of 300 French or more) The mixture was melt mixed and pelletized in a 400 Pent extruder.

This was injection molded in the same manner as in Example 1, and warpage and Izod impact strength were measured. The results are shown in Table 1. Comparative Examples 6 to 9 Molding was performed in exactly the same manner as in Comparative Example 5, except that the blending amounts of the wind component and the 'B} component were changed as shown in Table 1, and warp and Izod impact strength were measured.

The results are shown in Table 1. Comparative Examples 5 to 9 show that polyester resins containing glass fibers with a high content of long fibers of length 300 mm or more cause significant warpage in molded products even when the amount of glass fibers is only a few percent. ing. Ship's side selection'i-R kiW omitted*

[Brief explanation of the drawing]

FIG. 1 is a graph showing an example of the relationship between L/D of glass fiber, Izod impact strength, and warping. In the figure, the horizontal axis represents the ratio of the average length L to the average diameter D of the glass fibers, and the vertical axis represents the Izod impact strength (k9 one skin/arc) or warp deformation (side). Curve 1 shows the relationship between L/○ and Izod impact strength, and curve 2 shows the relationship between L/○ and warp deformation. Juice diagram

Claims (1)

[Claims] 1. A polyester resin composition containing (A) polybutylene terephthalate (B) glass fiber and (C) a polyfunctional compound selected from a polyepoxy compound, a polyisocyanate compound, an epoxysilane compound, or an aminosilane compound. A glass fiber containing 20% by weight or less of fibers having a length of 300μ or more and having a ratio of average length to average diameter of 10 to 22 as component (B). Reinforced polyester resin composition. 2 10 to 60% by weight of (B) based on the total amount of the resin composition
The composition according to claim 1, characterized in that it contains glass fibers. 3 0.01 to 10% by weight of (based on the total amount of the resin composition)
C) The composition according to claim 1, which contains a polyfunctional compound.