JP3375728B2 - Thermosetting resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition having vibration damping performance. [0002] Thermosetting resins such as unsaturated polyester resins, epoxy resins, and melamine resins have rigidity, heat resistance,
Due to its excellent solvent resistance and morphological stability, it is widely used in various fields such as building materials, furniture, and composite materials with metals. Among these application fields, for example, when a thermosetting resin is used as a building material, it resonates due to vibration and causes noise. As a method of suppressing the vibration of the thermosetting resin, the present inventors have previously proposed a method of blending a thermosetting resin with a thermoplastic block copolymer having a specific structure (Japanese Patent Application Hei 5-106244).
However, although the composition of the thermosetting resin and the thermoplastic block copolymer obtained by this method shows a great improvement effect in terms of vibration damping performance, the compatibility of both components is not necessarily sufficient, and In many cases, a time-consuming and phase separation problem occurs. SUMMARY OF THE INVENTION An object of the present invention is to solve the problem of compatibility between a thermosetting resin and a thermoplastic block copolymer, and to achieve excellent vibration damping performance. It is to obtain a thermosetting resin composition. Means for Solving the Problems The present inventors have studied a method of suppressing the vibration of a thermosetting resin by a method completely different from the conventional method, and as a result, it has been found that a specific block is not used. Heavy
The present inventors have found that a thermosetting resin composition having sufficient vibration damping performance and excellent workability can be obtained by using a fibrous material containing a coalesced substance, and the present invention has been accomplished. That is, according to the present invention, the above object is
A polymer block (A) comprising at least one vinyl aromatic monomer and having a number average molecular weight of 2500 to 40000, and isoprene or a mixture of isoprene and butadiene ;
A mixture having a 3,4-bond and 1,2-bond content of 30% or more, and a tan δ peak temperature of −
A fiber and a thermosetting resin comprising a block copolymer having a number average molecular weight of 30,000 to 300,000 or a hydrogenated product thereof as one component of a constituent polymer, comprising a polymer block (B) having a temperature of 20 ° C. or higher. This is achieved by providing a thermosetting resin composition comprising: [0006] In the thermosetting resin composition of the present invention,
By impregnating and laminating a fibrous block copolymer with a semi-solid thermosetting resin such as a liquid or paste, molding can be performed very easily. The thermosetting resin used in the present invention is a resin which has fluidity and plasticity in a normal state and is cured by heating. Examples thereof include unsaturated polyester resins, epoxy resins, melamine Resins, alkyd resins, phenolic resins and the like. The first component of the block copolymer used in the present invention is a vinyl aromatic monomer such as styrene, α-methylstyrene, 1-vinylnaphthalene,
2-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4- (phenylbutyl) styrene and the like are the most preferable. Is styrene. As the second component of the block copolymer used in the present invention, isoprene alone or a combination of isoprene and butadiene is suitable.
When other monomers are used, for example, when butadiene is used alone, even when the 1,2-bond content is increased, the temperature at which the vibration damping performance is exhibited is lower than −20 ° C., and is actually used. The function at temperature cannot be obtained, and it has little practical significance. In the case of isoprene, a 3,4-bond and 1,
2- By setting the bond content to 30% or more,
Since the vibration damping performance is exhibited in a practical temperature range from about 20 ° C. to about 50 ° C., it is possible to cope with a wide range of applications, which is extremely significant in practical use. When isoprene and butadiene are used in combination, if the proportion of isoprene is 30% or more, the vibration damping performance is exhibited at a temperature of -20C or more. The form of the polymer block (B) may be any of random, block and tapered. In the present invention, the content of 3,4-bond and 1,2-bond in the polymer block (B) is 30%
It is necessary to be above (or 100%). If this value is less than 30%, sufficient vibration damping performance cannot be obtained in a normal operating temperature range, which is not preferable. The polymer block (B) needs to have a peak temperature of the main dispersion of tan δ (loss tangent) obtained by viscoelasticity measurement of −20 ° C. or higher. -2
If there is only a peak at a temperature lower than 0 ° C., sufficient vibration damping performance cannot be obtained in a normal temperature range. [0013] The molecular weight of the polymer block comprising a vinyl aromatic monomer must be in the range of 2500 to 40000. If the molecular weight is less than 2500, the mechanical properties decrease, while if the molecular weight exceeds 40,000, the melt viscosity increases, and it becomes difficult to fiberize as described later. The polymer block composed of isoprene or a mixture of isoprene and butadiene may be used by hydrogenating at least a part of the carbon-carbon double bond in the block. In that case, the hydrogenation rate depends on the required heat resistance,
Determined according to the level of weather resistance, usually 50 mol%
As described above, it is preferably at least 70 mol%, and when higher heat resistance and weather resistance are required, the hydrogenation rate is preferably at least 80 mol%. If the degree of hydrogenation is less than 50 mol%, the effect of improving heat resistance and weather resistance cannot be expected. The ratio of the polymer block (A) comprising a vinyl aromatic monomer in the block copolymer is 5%.
It may be in the range from 50% by weight to 50% by weight. If the proportion is less than 5% by weight, the mechanical properties of the block copolymer may be insufficient. On the other hand, if it exceeds 50% by weight, the processing becomes difficult because the viscosity becomes extremely high. However, the vibration damping performance may be reduced. The molecular weight of the obtained block copolymer is 30.
It needs to be in the range of 000 to 300,000.
When the molecular weight is smaller than 30,000, the mechanical properties such as strength at break and elongation of the block copolymer itself are reduced. If the molecular weight exceeds 300,000, processability deteriorates. From this point, the molecular weight of the block copolymer is more preferably in the range of 80,000 to 250,000. The block copolymer used in the present invention can be obtained by a known method. In addition, when hydrogenation is performed, a known method is employed. When fiberizing the block copolymer of the present invention, various known thermoplastic resin spinning methods are employed. Spinning is performed by using the block copolymer alone, and mixed spinning with other fiber-forming thermoplastic resin or composite spinning is also possible. The melt spinning device used here may be substantially the same as the device used when melt spinning the fiber-forming thermoplastic resin. That is, for example, a type in which a gear pump is connected to a screw extruder is sufficient.
Depending on the spinning temperature, spinning extrusion pressure, extrusion speed, spinning hole diameter and winding speed, the denier composition of the fiber to be produced can be changed in various ways, but in this regard it is the same as in the case of melt spinning of ordinary synthetic fibers. . The spinning temperature is usually 180 to 250 ° C, and the spinning draft is 5 to 2
The winding speed is generally preferably in the range of 20 to 1000 m / min. The fiber wound in this manner may be drawn as in the case of ordinary thermoplastic synthetic fibers, but may not be drawn, and steps such as heat treatment may be omitted. Therefore, the yarn making process is very simple and economical in this respect. The thickness of the fiber thus obtained is several denier or more as in the case of ordinary thermoplastic synthetic fibers, and can be arbitrarily selected from this range. Therefore, it can be used as a multifilament, a filament, and also as a staple. The cross section of the resulting fiber form, in addition to flat cross section of a conventional round cross-section, polygonal cross-section, multilobal cross-section, may be any of hollow cross section or the like. Examples of materials used when forming a fiber by combining with another resin include polyolefin such as polypropylene and polyethylene, and polyethylene terephthalate.
Thermoplastic resins such as polyesters such as (PET) and polyamides are used. In this case, the cross-sectional shape of the fiber may be any of a concentric core-sheath type, an eccentric core-sheath type, a multi-core sheath type, a bimetal type, a multilayer lamination type, and the like. In the case of composite spinning or mixed spinning, the ratio of the block copolymer or a hydrogenated product thereof to the entire polymer constituting the fiber is 5% by weight or more, and more preferably 15% by weight or more from the viewpoint of vibration damping performance. It is. [0023] The more the resulting fibers are woven by a known method, net, mat, is used in the nonwoven fabric. The shape is determined according to the purpose of use, and is not particularly limited. Further, in addition to the above-mentioned method, a method of directly forming a nonwoven fabric from melt spinning by melt blowing and using the same can also be adopted. In the present invention, the method of compounding the fiber and the thermosetting resin includes impregnating a woven, net , or nonwoven fiber with a liquid thermosetting resin, or pressing a semi-solid resin into a press. After impregnating by applying pressure,
A method of curing by heating this is adopted.
It is also possible to handle the resin impregnated as a so-called prepreg. In addition, the mixture obtained by adding and mixing the resin in the state of a thread or cotton is cast,
A method of molding by pressing or the like and curing by heating is adopted. The thermosetting resin composition of the present invention can be used, for example, in boats and other boats, motorcycles, automobiles and other exterior materials, wall materials and floor materials, construction materials such as golf clubs, tennis rackets and other sports equipment, and various machines. It can be used for a wide range of applications such as building materials, exterior materials for vehicles, interior materials, etc. in a form laminated with metal materials such as iron and aluminum, in addition to shafts, electronic circuit boards, housings of various devices, and the like. The present invention will be described more specifically with reference to the following examples. The measured values in the examples were obtained by the following methods. The loss coefficient (η) indicating the vibration damping performance was determined by a resonance method in which a specimen was vibrated by a vibrator and the degree of resonance of the specimen was measured. Example 1 and Comparative Example 1 It is composed of two styrene blocks having a number average molecular weight of 8000 and an isoprene block and has a total number average molecular weight of 1200.
00, the 3,4-bond of the isoprene block and
By hydrogenating a styrene-isoprene-styrene block copolymer having a 1,2-bond content of 45% and a tan δ peak temperature of 0 ° C., a hydrogenated block having an isoprene block hydrogenation ratio of 93% is obtained. A polymer was obtained. The obtained block copolymer was subjected to a spinning temperature of 200 using a conventional spinning machine in which a gear pump was connected to a screw type extruder.
At a spinning speed of 500 m / min to obtain a fiber having a single fiber fineness of 40 denier and a fiber length of 64 mm. Next, after mixing the fibers, carding and laminating the web were carried out at 150 ° C.
× 1 minute hot air treatment to prepare a mat. Mat thickness is 2
mm and the basis weight was about 0.15 kg / m ² . The mat was impregnated with an epoxy resin according to the formulation shown in Table 1 and cured to obtain a molded product. Table 1 shows the measurement results of the loss coefficient of the obtained molded body. For comparison, the loss factor of a molded article molded using the PET mat obtained in the same manner as described above was also measured and is shown in Table 1. [Table 1] As can be seen, the composition of the present invention has improved vibration damping properties. Example 2 and Comparative Example 2 The hydrogenated block copolymer used in Example 1 was used as a core component, PET having an intrinsic viscosity of 0.64 was used as a sheath component, and the weight ratio of the core component to the sheath component was 50. / 50 core-sheath fibers were prepared by melt composite spinning. Spinning condition is temperature 29
The temperature was 0 ° C. and the winding speed was 1000 m / min. Drawing was performed by a conventional method to obtain concentric core-sheath composite fibers having a short fiber fineness of 6 denier and a fiber length of 51 mm. To this, 20% of a 3 denier polyester-based heat-fusible fiber was mixed, cut and laminated to form a web, followed by hot air treatment to prepare a mat.
The thickness of the mat is is 5mm, is with the eyes about 0.5kg / m
It was ² . The mat was impregnated with various thermosetting resins according to the formulation shown in Table 2 and cured to obtain a molded product. Table 2 shows the measurement results of the loss coefficient of the obtained molded body. [Table 2] [0037] According to the present invention, by using a block copolymer with fibrous, improved compatibility with the thermosetting resin and the block copolymer, a sufficient damping performance Has,
A thermosetting resin composition having excellent processability can be obtained .

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-203456 (JP, A) JP-A-1-223143 (JP, A) JP-A-3-759 (JP, A) JP-A-5-759 202287 (JP, A) JP-A-5-279543 (JP, A) JP-A-6-293854 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 53/00 C08J 5 /twenty four

Claims (1)

(57) Claims: 1. A polymer block (A) comprising at least one vinyl aromatic monomer and having a number average molecular weight of 2,500 to 40,000, isoprene or isoprene and block. Consisting of a mixture of tadiene, with 3,4-bonds and 1,2
A block copolymer having a bond content of 30% or more and a polymer block (B) having a tan δ peak temperature of −20 ° C. or more and a number average molecular weight of 30,000 to 300,000 or a hydrogenated product thereof; A thermosetting resin composition comprising a composite of a fiber and a thermosetting resin containing as one component of a constituent polymer.