JPH07103306B2 - Fiber-reinforced polyurethane resin composition excellent in low-temperature rapid curing property - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has a fast curability capable of being cured in a temperature range of 40 to 60 ° C. in 1 to 3 minutes, and the cured product has impact resistance and heat resistance. The present invention relates to a fiber-reinforced polyurethane composition having excellent rigidity.

[Conventional technology]

In recent years, in the field of automobile parts, the use of plastics has been increasing along with weight reduction and diversification of designs. In particular, long-fiber reinforced plastics, which have high rigidity as structural members and semi-structural members, are being directed.

Conventionally, unsaturated polyester resins have been the mainstream as this type of resin. Sheet molding compound (SMC) is known as a method to efficiently produce this type of resin, but it requires high temperature and high pressure and the investment in equipment is large. A resin injection method is also known, in which a solid reinforcing material is set, and after the mold is closed, a liquid unsaturated polyester resin composition is injected and the resin is cured in the mold, but the curing is usually slow and the production efficiency is low. And generally, this kind of resin is inferior in impact resistance.

On the other hand, polyurethane resin is known to provide a cured product having good impact resistance, but generally has poor heat resistance. Therefore, in order to improve heat resistance, there is a method of increasing the crosslink density by using a polyfunctional polyol. In this case,
Gelation is quick, but the reaction rate immediately after curing is low, and unreacted isocyanate groups and hydroxyl groups are likely to remain, so the physical properties are slow to develop, and the physical properties that can be practically used cannot be obtained unless post-cure or days elapse. was there.

When the reactivity is increased by using a conventional urethane-forming catalyst, the viscosity of the liquid increases too quickly, and the urethane composition does not sufficiently penetrate into the long fiber mat and is cured. On the other hand, if the reaction is adjusted so that the liquid permeates into the long fiber mat, the physical properties at the time of curing are inferior, the demolding requires a long time, and the productivity is low.

[Problems to be Solved by the Invention]

The present invention provides a fiber-reinforced polyurethane resin composition having good permeability to long fiber mats, excellent physical property expression at low temperature and fast curing, and cured products having excellent impact resistance, heat resistance, and strength. is there.

[Means for Solving the Problems]

As a result of diligent studies, the present inventors have found that the combination of a specific urethane composition, a specific catalyst, and a long-fiber mat has excellent low-temperature fast-curing properties and the physical properties of molded articles, leading to the present invention. It was

That is, the present invention relates to a fiber reinforced polyurethane resin composition comprising a long fiber mat and a polyurethane resin, wherein the polyurethane resin is a. Organic polyisocyanate b. Polyether polyol having a molecular weight of 300 to 700 and having 3 or more functional groups c. Ethylene glycol And / or 1,3-butanediol d. A curing catalyst comprising an imidazole compound represented by the general formula (1) (M = 1 to 4, n = 1 to 4) The ratio of a and b + c is 130/100 to 180/100 weight ratio, and the ratio of the polyurethane resin composition and the long fiber mat is 90/10.
The present invention relates to a fiber-reinforced polyurethane resin composition, characterized in that the weight ratio is up to 50/50.

This composition may be molded by setting a long fiber mat in the mold in advance and injecting the polyurethane resin composition after closing, or by injecting before the mold closing mold depending on the structure of the mold. it can. Injection is performed by a high pressure reaction injection molding machine (RI
M) or a two-liquid mixing low-pressure injector is convenient. Examples of the organic polyisocyanate (a) that can be used in the present invention include aliphatic polyisocyanates such as hexamethylene-1,6-diisocyanate, 2,2,4- or 2,4,4-trimethylhexahexane. Methylene-1,6-diisocyanate, etc .; Alicyclic polyisocyanates such as cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, etc .; Aromatic polyisocyanates such as P-phenylene diisocyanate, Tolylene-2,
4- or -2,6-diisocyanate, diphenylmethane-2,4'- or -4,4'-diisocyanate, naphthylene-1,5-diisocyanate, xylylene-1,3- or -1,4-diisocyanate, diphenylether- 4,4 ′
-Diisocyanates and the like.

In addition, polyphenylene polymethylene polyisocyanate of the type obtained by condensing aniline and formalin and then phosgenating, or diphenylmethane diisocyanates that are liquid at room temperature and have a carbodiimide group or a uretone imine group, or a urethane bond, an allophanate bond, a biuret bond and Modified polyisocyanates containing a uretdione ring or the like can also be used.

Further, an isocyanate-based prepolymer obtained by excessively reacting the polyol with the polyisocyanate can also be used.

Among these, particularly preferred organic polyisocyanates are
Examples of the diphenylmethane diisocyanate-based polyisocyanate include polyphenylene polymethylene polyisocyanate which is liquid at room temperature and has a low viscosity and high rigidity, and diphenylmethane diisocyanate having a carbodiimide group or a uretone imine group.

Examples of the polyether polyol (b) that can be used in the present invention include polyols such as glycerin, trimethylolpropane and pentaerythritol, amino alcohols such as diethanolamine, triethanolamine and tripropanolamine, ethylenediamine,
It is a polyether polyol having a molecular weight of 300 to 700 and a functional group number of 3 or more obtained by adding amines such as 1,6-hexanediamine, diethylenetriamine and toluylenediamine, and a mixture thereof with ethylene oxide, propylene oxide and the like.

In this case, when the molecular weight of the polyether polyol is less than 300, the reaction is too fast to control the reaction by the catalyst, and the impact resistance of the cured product deteriorates. On the other hand, when the molecular weight of the polyether polyol is more than 700, the cured product cannot have rigidity and heat resistance as a structural material. And the molecular weight of polyether polyol is 30
Even in the range of 0 to 700, when the number of functional groups of the polyether polyol is 2, similarly, practical rigidity and heat resistance cannot be obtained.

The chain lengthening agent (c) that can be used in the present invention includes
It is ethylene glycol, 1,3-butanediol, or a mixture thereof. In this case, other compounds such as 1,4-butanediol, 1,6 hexanediol, dipropylene glycol and diethylene glycol are generally well known as chain extenders in polyurethane compositions, but 1,4
Since solids of butanediol and 1,6-hexanediol are solid at winter at room temperature, a dissolution step is required when blending with polyether polyol, and winter separation of the blended liquid is also undesirable. Further, when a chain length side having a relatively large molecular weight such as dipropylene glycol, diethylene glycol and 1,6-hexanediol is used, the cohesive force of the hard segment of urethane becomes weak, resulting in good rigidity and heat resistance. I can't get it.

Isocyanate group (NCO) / hydroxyl group (O
The equivalent ratio of (H) is 0.9 to 1.2, preferably 1.0 to 1.
Is 1.

The ratio of organic polyisocyanate and polyol (polyether polyol + chain lengthening agent) is 130/100 to 180/100.
When the amount of the organic polyisocyanate is less than this range, the heat resistance is poor, and when the amount of the organic polyisocyanate is more than this range, the impact resistance tends to be poor.

The ratio (weight) of the polyether polyol (b) and the chain extender (c) used in the present invention is preferably in the range of 100/4 to 100/100. Particularly preferably, it is in the range of 100/5 to 100/60.

The curing catalyst (d) that can be used in the present invention is an imidazole compound represented by the general formula (1) (M = 1 to 4, n = 1 to 4 integer) Typical examples include 1,2-dimethylimidazole and 1-butyl-2-methylimidazole.

In the present invention, a urethanization catalyst known in the art may be used in combination. Typical examples are triethylamine, tripropylamine, tributylamine, N-methylmorpholine, N, N-dimethylcyclohexylamine, N, N-
Tertiary amines such as dimethylbenzylamine, N, N, N ', N'-tetramethylhexamethylenediamine, triethylenediamine, 1,8-diazabicyclo (5,4,0) undecene-7 or their organic compounds Acid salt, stanna octoate,
Examples thereof include organic metal compounds such as dibutyltin dilaurate and zinc naphthenate.

The long fiber mat that can be used in the present invention includes:
Examples include chopped strand mats such as glass fiber, carbon fiber and aramid fiber, continuous strand mats, surfacing mats, cloths and roving cloths. 2 of these long fiber mats
It is also possible to use together more than one species.

In the present invention, the ratio of the polyurethane resin composition to the long fiber mat is preferably 90/10 to 50/50 weight ratio. If the ratio of the long fiber mat is too small, the rigidity becomes insufficient, while if it is too large, impregnation injection of the polyurethane resin composition into the long fiber mat becomes difficult, which is not preferable.

In the present invention, various metal ropes and synthetic resin net-like moldings may be used in combination with the long fiber mat, if necessary.
Further, in the present invention, a foaming agent, a flame retardant, a coloring agent, various fillers, an internal mold release agent, and other processing aids can be added if necessary.

〔The invention's effect〕

Since the fiber-reinforced polyurethane resin composition of the present invention is fast-curing, and the cured product has excellent impact resistance, heat resistance and rigidity, for example, bumper beams, floor panels, door inner panels, door liners, heads in the automobile field. It is extremely useful as a structural member for liners, dashboards, pillar covers, and other general industrial materials.

〔Example〕

Next, the present invention will be described more specifically with reference to Examples.
The present invention is not limited to these.

The physical properties were measured by the following methods.

Measurement item Measurement method Specific gravity JIS K-7112 Bending elastic modulus JIS K-7203 Bending strength JIS K-7203 With Izod impact notch JIS K-7110 Heat deformation temperature (18.5 kgf / cm ² load) JIS K-7207 Example 1 3, Comparative Examples 1 and 2 Glassron M8609 (glass continuous mat, made by Asahi Fiberglass, trade name) of the same size is placed in a 50 ° C mold with a cavity size of 300 × 300 × 3 mm, and 25 ° C Millionate MR200 is placed there. (Polyphenylene polymethylene polyisocyanate NCO content 30.9%, Nippon Polyurethane Industry product name) 150 parts by weight, ADEKA Polyether AM30 (glycerin-based polyether polyol hydroxyl value 540, Asahi Denka Kogyo product name) 93.9 parts by weight, ethylene glycol 6.1
The parts by weight and the curing catalyst shown in Table 1 were mixed by stirring with a lab mixer, and the mold was clamped immediately after the injection. Then, two minutes after the mold was clamped, the mold was removed and the tack on the surface of the molding plate was examined.
The catalyst amount was adjusted so that the gel time was 20 to 30 seconds in each formulation.

The results are shown in Table 1.

Product name of Sankyo Air Products ・ The amount of catalyst used is% by weight based on the polyurethane resin composition.

Examples 4 to 6 and Comparative Examples 3 to 4 Glaslon M8609 was placed in the same 50 ° C. mold as in Example 1, and the A and B 2 components shown in Table 2 were mixed into the low-pressure two-liquid mixture injection machine (polyurethane engineering MU203H). To inject,
Table 2 shows the composition and physical properties of the molded plate obtained by demolding after 3 minutes of mold clamping.

Product name manufactured by Asahi Denka Co., Ltd. Example 7, Comparative Examples 6 to 7 Glazron M8609 was placed in a 50 ° C. mold having a cavity size of 300 × 200 × 2.5 mm, and after the mold was closed, the A and B2 components at 30 ° C. shown in Table 3 were added. A high-pressure reaction injection molding machine (RIM) (MC102 made by Polyurethane Engineering) was used to inject it into the mold, and after 3 minutes, the mold was removed to obtain a molded plate. The composition and physical properties are shown in Table 3.

Product name made by San-Apro

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Claims (1)

[Claims] 1. A fiber reinforced polyurethane resin composition comprising a long fiber mat and a polyurethane resin, wherein the polyurethane resin is a. Organic polyisocyanate b. Polyether polyol having a molecular weight of 300 to 700 and having 3 or more functional groups c. Ethylene Glycol and / or 1,3-butanediol d. A curing catalyst comprising an imidazole compound represented by the general formula (1) (M = 1 to 4, n = 1 to 4) The ratio of a and b + c is 130/100 to 180/100 weight ratio, and the ratio of the polyurethane resin composition and the long fiber mat is 90/10.
A fiber-reinforced polyurethane resin composition, characterized in that the weight ratio is up to 50/50.