JPH0284417A - Fiber-reinforced unsaturated polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition outstanding in molding processability and impact resistance, improved in mechanical strength and elastic modulus, and suitable for members for automobile outer plies by blending specific components such as unsaturated polyester and polyhydric alcohol, etc., at specified proportion. CONSTITUTION:The objective composition can be obtained by blending (A) an unsaturated polyester 115-210mg KOH/g in hydroxyl value and <=5mg KOH/g in acid value, prepared from a dicarboxylic acid (anhydride) containing 40-100mol$ of unsaturated dicarboxylic acid (anhydride) and a primary hydroxyl group-contg. polyhydric alcohol, (B) a polyhydric alcohol 35-1100mg KOH/g in hydroxyl value, having two or more hydroxyl groups, (C) a liquid polyisocyanate compound 10-2000cps in viscosity at 25 deg.C, having terminal group of the formula, (D) a polymerizable vinyl monomer, and (E) fiber, in such amounts as: (1) the component B: <=50wt.% of the components A+B; (2) the component A+B: 50-80wt.% of the component A+B+C; and (3) the isocyanate group in the component C: the hydroxyl group in the component B=0.75:1.2 (molar ratio).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel fiber-reinforced unsaturated polyester resin composition that has excellent impact resistance and improved moldability.

[Prior art]

Usually, unsaturated polyester resin is produced by a dehydration condensation reaction between an unsaturated dicarboxylic acid or its acid anhydride, a mixture of a saturated dicarboxylic acid or its acid anhydride, and a polyhydric alcohol, and a polymerizable vinyl monomer. It can be obtained by mutually dissolving it with a polymerization inhibitor, etc., and is liquid at room temperature.

Cured products of such unsaturated polyester resins have excellent mechanical strength, chemical resistance, heat resistance, etc. Taking advantage of these properties, unsaturated polyester resins can be used for casting, painting, and decorative laminates. It is used as a raw material. However, because it lacks strength and toughness, it must be combined with fibers to be used as a structural material. That is, in the form of fiber-reinforced unsaturated polyester resin, it is widely and effectively used for molding various purposes such as boats, ships, bathtubs, water tanks, septic tanks, and chemical storage tanks.

As described above, it is already a well-known method to combine unsaturated polyester resin and fiber to obtain a fiber-reinforced unsaturated polyester resin composition with excellent impact resistance.
For example, it is insufficient for use in applications requiring higher impact resistance, such as automobile outer panel members, bumpers, and supports, helmets, and the like.

In order to obtain a molded article with higher impact resistance from a fiber-reinforced unsaturated polyester resin composition, there is a method of using an unsaturated polyester resin with a relatively high molecular weight, and an unsaturated polyester resin with excellent flexibility and toughness. how to,
Furthermore, a method is known in which a large amount of mu, which is a reinforcing material, is used.

However, when using an unsaturated polynisglue resin with a high molecular weight, although it is liquid at room temperature, it has a high viscosity and has a problem with impregnating the fibers, making it unsatisfactory in terms of molding workability and making it difficult to obtain. The appearance, strength and elastic modulus of the molded product are also not fully satisfactory.

Furthermore, even when conventionally known urethane-modified unsaturated polyester resins with excellent flexibility and toughness are used, it is possible to provide fiber-reinforced unsaturated polyester resin compositions with improved impact resistance, but molding workability is The disadvantage is that it is not always possible to obtain a fully satisfactory result. For example, when producing a sheet-like molding material that is non-sticky and has excellent fluidity during molding and hot press molding to produce a molded product with excellent impact resistance, high molecular weight unsaturated polyester resin, metal Although it is well known to make sheet molding compounds from oxides or metal hydroxides and fibers, the impact resistance is not sufficient, so an improvement method is to use unsaturated polyester resins and polyisocyanate compounds. A method was proposed to obtain a composition with high impact resistance by combining it with fibers.

USP 4,327.145 (1982) states that the hydroxyl value is 2 (1 to 55 mg KOFI/g), the acid value is 5 to 20 mg KOH/g, and the ratio of hydroxyl value to acid value is in the range of 1.7 to 10. An easy-to-handle sheet molding compound composed of a resin composition consisting of an unsaturated polyester, a polymerizable vinyl monomer, and a polyisocyanate compound, and glass fibers is described. Due to its relatively high molecular weight, the viscosity of the liquid unsaturated polyester resin dissolved in the polymerizable vinyl monomer is high, making it difficult to impregnate fibers.Furthermore, it remains unreacted in the sheet molding compound. The isocyanate groups of the unsaturated polyester and the carboxyl groups of the unsaturated polyester react with each other during hot press molding to generate carbon dioxide gas, which tends to cause defects such as whitening and blistering in the molded product.

Whitening and blistering in the molded product cause variations in the mechanical strength and physical properties of the molded product, making it difficult for the material to be reliable.

USP 4.067, 845 (1978) states that unsaturated polyesters with a molecular weight of 800 to 5000 have an acid value of 14 mg K Off / g or more and a molar ratio of hydroxyl groups to carboxyl groups in the range of 0.8 to 5.7. ,
A press-forming sheet, molding,
It describes the compound. This method involves the reaction of the hydroxyl group of an unsaturated polyester with the incyanate group of a polyisocyanate compound, and the reaction of the carboxyl group of the unsaturated polyester with the isocyanate group of the polyisocyanate compound to obtain a sheet molding compound for press molding. The viscosity is increased by utilizing a reaction involving carbon dioxide gas and a reaction between the carboxyl group and metal oxide or metal hydroxide, which also prevents defects such as whitening and blistering caused by carbon dioxide gas in molded products. Easy to occur.

[Problem that the invention seeks to solve]

As a result of intensive studies aimed at improving the various drawbacks mentioned above, the present inventors have found that the hydroxyl value obtained from a dicarboxylic acid containing 40 to 100 mol% of an unsaturated acid and a polyhydric alcohol having a primary hydroxyl group has been found. 115-210m
Impact resistant polyester is made of unsaturated polyester having a specific range of gK[lH/g or less and acid value of 5 mgKOH/g or less, a polyisocyanate compound with a specified end group and viscosity, a polymerizable vinyl monomer, and fibers. It was discovered that a fiber-reinforced unsaturated polyester resin composition with improved properties, strength, elastic modulus, and molding processability could be obtained, and the applicant first filed a patent application (Japanese Patent Application No. 1982-215492).

However, as a result of subsequent research, it was found that the unsaturated polyester has at least two hydroxyl groups in the molecule and has a hydroxyl value of 35 to 1100 mg KOIl/
It has been found that a fiber-reinforced unsaturated polyester resin composition with improved impact resistance and moldability can be obtained by adding a specific range of polyhydric alcohol (g).

[Failure to solve the problem]

That is, the present invention uses unsaturated polyester (A), polyhydric alcohol (B), polyisocyanate compound (C), polymerizable vinyl monomer (D), and fiber (E) as main components.
(A) is an unsaturated dicarboxylic acid or an acid anhydride containing a dicarboxylic acid or anhydride thereof containing 40 to 100 mol% and a polyhydric alcohol having a primary hydroxyl group. 115-210mg
KOH/g, an unsaturated polyester with an acid value of 5 mgKOH/g or less, ■ (C) is a liquid polyisocyanate compound with a convex CI+2ONCO terminal group and a viscosity of 10 to 2000 cps at 25°C, ■ ( B) has at least two hydroxyl groups in the molecule and has a hydroxyl value of 35 to 1100 mgK[]
II/g polyhydric alcohol, and the following conditions (i) (ii) '(iii) and (iv) (i)
(B) is 50% by weight or less, preferably 10 to 50% by weight based on the total amount of (A) and (B), (ii) (
The total amount of A) and (B) is in the range of 50 to 85% by weight, preferably 60 to 80% by weight, based on the total amount of (A), (B) and (D), (ii) (C) The isocyanate group is (A)
and (B) 0.75 to 1.2 times by mole, preferably 0.85 to 1.0 times by mole, (iv) (
E) has improved moldability and impact resistance, characterized in that it satisfies 50 to 70% by weight based on the total amount of (A), (C), (D), (E) and (B). It is a fiber-reinforced unsaturated polyester resin composition.

Examples of unsaturated dicarboxylic acids or acid anhydrides for producing the unsaturated polyester (A) in the present invention include maleic acid, maleic anhydride, fumaric acid, and saturated dicarboxylic acids or acid anhydrides thereof. Examples include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, het's acid, and tetrahydrophthalic anhydride.

In addition, examples of polyhydric alcohols having a -grade hydroxyl group include ethylene glycol, diethylene glycol, 1.4
-Butanediol, neopentyl glycol, etc. can be mentioned. Polyhydric alcohols containing secondary hydroxyl groups, such as propylene glycol, dipropylene glycol, and bisphenol A-propylene oxide adducts, can also be used in combination, but the amount is preferably 5 mol % or less. If an unsaturated polyester prepared using more than 5 mol % of a polyhydric alcohol containing secondary hydroxyl groups is used, only a composition with low impact resistance will be obtained and the object of the present invention cannot be achieved.

Examples of the polymerizable vinyl monomer (D) that can be mixed with this unsaturated polyester include styrene, chlorostyrene, vinyltoluene, (meth)acrylic acid, and derivatives thereof. In preparing the unsaturated polyester resin by the method of the present invention, the unsaturated polyester can be used in an amount of 50 to 70% by weight, and the polymerizable vinyl monomer can be used in an amount of 30 to 50% by weight.

The polyisocyanate compound (C) that can be used in the composition of the present invention has a terminal group and a viscosity of 10 to 2000 cps at 25°C.
, preferably 30 to 1500 cps, i.e. carbodiimide modified 4°4°-diphenylmethane diisocyanate (containing 20 to 30% carbodiimide; e.g. l5onate 1
Compound (commercially available under the trade name 43L), 4,4
Polyether prepolymers of ゛-diphenylmethane diisocyanate (for example, a compound commercially available under the trade name l5onate 181), polyester prepolymers of 4.4°-diphenylmethane diisocyanate (for example, a compound commercially available under the trade name l5onate 240) etc. can be mentioned.

The amount of these polyisocyanate compounds (C) to be used is in the range of 0.75 to 1.2 moles of isocyanate groups relative to the hydroxyl groups of the unsaturated polyester (A).

As the fibers (E), glass fibers, carbon fibers, and aramid fibers are preferable, and glass fibers are particularly preferable, considering strength, affinity with resin, price, and the like.

Examples of the polyhydric alcohol (B) having at least two hydroxyl groups in the molecule and a hydroxyl group of 35 to 1100 mgKOH/g include diethylene glycol triethylene glycol, dipropylene glycol, 1.5-bentanediol, 1.6 Examples include -hexanediol, polyethylene glycol and polypropylene glycol with a molecular weight of 200 to 3,000, and polytetramethylene glycol with a molecular weight of 200 to 3,000, but glycols having -class hydroxyl groups are preferred, particularly polyethylene glycol and polytetramethylene glycol. is preferred.

The unsaturated polyester resin composition of the present invention contains not only conventional polymerization inhibitors such as hydroquinone, parabenzoquinone, and methyl hydroquinone, but also benzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl perbenzoate, and the like. Conventional curing catalysts such as dimethylaniline, conventional curing accelerators such as cobalt naphthenate, conventional urethanization catalysts such as cobalt octoate, dibutyltin dilaurate, etc. can be used.

The unsaturated polyester resin composition of the present invention can be used in press molding, reaction injection molding (RIM molding), etc., which are commonly used in the industry in which the composition is used.

The resin composition of the present invention can be used, for example, in the following embodiments. One is an unsaturated polyester resin that is liquid at room temperature and obtained by mutually dissolving unsaturated polyester (A) with a polymerizable vinyl monomer (D), a polyhydric alcohol (B), and a polymerization inhibitor. After uniformly mixing the liquid polyisocyanate compound (C) and a thermally decomposable radical polymerization initiator, the fiber (E) is impregnated with the liquid polyisocyanate compound (C), and a urethane reaction is performed in advance to increase the viscosity (so-called B stage) and make it sticky. To produce a sheet-like or block-like molding material that is free from molding and has excellent fluidity during molding. The sheet-like or block-like molding material without stickiness thus produced can be processed into a molded product with excellent impact resistance by carrying out a radical polymerization reaction by hot press molding.

Still another method is to fill a mold made in the desired shape with fibers (E) and use the method described above to (
The unsaturated polyester resin which is liquid at room temperature obtained from A) and (D> and the polyisocyanate compound (C) which is liquid at room temperature
) (a radical polymerization initiator is also added) are uniformly mixed and injected into a mold held at a predetermined temperature, allowing the urethanization reaction and radical polymerization reaction to occur almost simultaneously, resulting in excellent impact resistance. It can be processed into molded products.

〔Effect of the invention〕

In the present invention, specific components (A), (B), (C),
By blending (D) and (E) in a specific ratio,
A fiber-reinforced unsaturated polyester resin composition with improved impact resistance, strength, modulus of elasticity, and moldability is obtained.

The composition of the present invention is particularly suitable for applications requiring higher impact resistance, such as automobile outer panel members, bumper supports, helmets, and the like.

〔Example〕

Next, the present invention will be explained in detail with reference to Examples, but the present invention is not limited only to these Examples.

Hydroxyl number of the unsaturated polyester on each side [m
gKOIl/g) is determined by the acetylation method to obtain the acid value [:
mgKO1l/g) and viscosity [cps] are JIS
Measured according to K6901.

A falling weight impact test of the fiber-reinforced unsaturated polyester resin molding was conducted using a falling weight impact tester equipped with a computer data analysis device manufactured by CEAST (Italy). In the test, a test piece of size 10 cm x 10 cm and thickness of 3 mm was fixed to a pedestal with a hole of 50 mm in diameter with a force of 6 kg/-, and then a striker with a rounded tip with a diameter of 20 mm was fixed at 10.010/-. Drop the test piece at a speed of 2 seconds and punch out the test piece. The shock wave at this time is sensed by a strain gauge installed inside the striker, transmitted to the microcomputer, and the maximum impact load (P,,,) (Kgl, fracture initiation energy (El) [Kg '' Cm) (F WAX
(energy absorbed by E), fracture propagation energy (E
p) [Kg-cm) (F, , energy absorbed after) was calculated. The test was conducted three times, and the average value is shown. When evaluating impact resistance, Fll1lX
and Bi are important, and the larger the P1111111 and EiO values, the better the impact resistance. Ep indicates the behavior after fracture, and the larger the value of Hp, the more difficult it is for the material to completely fracture.

Synthesis Example (1) (Synthesis of unsaturated polyester resin rA-IJ) Isophthalic acid 13. 48
16.57 kg of neopentyl glycol, and 9.88 kg of ethylene glycol were charged, and stirring and heating were started while flowing nitrogen gas.

Thereafter, the temperature was gradually raised and a dehydration condensation reaction was carried out according to a conventional method at a maximum temperature of 205°C. The acid value of the reaction mixture is 4.
When the temperature reached 7, heating was stopped and the temperature was cooled to 120°C. Next, after charging 18.84 kg of fumaric acid, heating was started again and a dehydration condensation reaction was carried out at a maximum heating temperature of 225°C to obtain an unsaturated polyester having an acid value of 2.6 and a hydroxyl value of 151.9. Thereafter, the mixture was cooled to 170° C., and 11.5 g of hydroquinone and 2.5 g of rosebenzoquinone were added and mixed well. This unsaturated polyester was dissolved in styrene to obtain an unsaturated polyester resin (rA-IJ) containing 34.5% styrene.

The viscosity of rA-IJ at 25°C was 263 cps.

Synthesis Example (II) (Synthesis of unsaturated polyester resin rA-IIJ) Into the same reactor as Synthesis Example (1), 11.76 kg of isophthalic acid was added.
, 29°45 kg of diethylene glycol, and 16.44 kg of fumaric acid were charged and reacted in the same manner as in Synthesis Example (I) to synthesize an unsaturated polyester having an acid value of 4.8 and a hydroxyl value of 146.0. It was dissolved to obtain an unsaturated polyester resin (rA-I[J) containing 33.5% styrene. [A-I[J at 25°C
The viscosity was 130 cps.

Comparative synthesis example (1) (Synthesis of unsaturated polyester resin rBJ) Synthesis example (I)
Using a reactor similar to that of
0g was reacted in the same manner as in Synthesis Example (I), and the acid value was 25.
．． After synthesizing the unsaturated polyester of No. 3, it was dissolved in styrene, and the styrene content was 40°0% and the viscosity at 25°C was 128.
An unsaturated polyester resin (rBJ) of 0 cps was obtained.

Example 1 Unsaturated polyester resin rA obtained in Synthesis Example (I)
-I J 1727g, hydroxyl value 369mg
KOII/g polyethylene glycol 740g and t
-Butyl perbenzony) After uniformly mixing 25 g,
Polyisocyanate compound (Isonate 143L
, manufactured by MO Kasei Co., Ltd.) was added thereto and mixed quickly and uniformly. This mixture is then continuously fed onto a polypropylene sheet by an SMC making machine to achieve a glass content of 6.
5% by weight, roll-shaped SM with a width of 45 cm and a thickness of 2 mm.
Created C. This SMC was wrapped in a cellophane film to prevent styrene from volatilizing, and then aged in a thermostatic chamber at 23° C. for 3 days. After aging, when the polypropylene sheet was peeled off, a non-adhesive, flexible SMC with good impregnability into glass fibers was obtained.

Next, 500g of this SMC was placed into a 27cm x 27cm
After cutting it into a size of
The molded product was held at f for 5 minutes to obtain a molded product with a size of 30 cm x 30 cm and a thickness of 3 mm. The obtained molded product is 10cm x
After cutting into 10 cm pieces, a falling weight impact test was conducted to evaluate impact resistance. The test results obtained are shown in Table 1. As can be seen from Table 1, it is clear that the addition of polyethylene glycol further improves the impact resistance.

Example 2 Unsaturated polyester resin rA- obtained in Synthesis Example (I)
I J 1910g, hydroxyl value 173mgK
OIl/g polytetramethylene glycol 818g5
t-Butyl perbenzoate 27g1 Polyisocyanate compound (Isonate 143L, manufactured by MO Kasei)
Impact resistance was evaluated in the same manner as in Example 1, except that the weight was changed to 772 g.

The obtained evaluation results are also shown in Table 1.

Reference Example 1 Unsaturated polyester resin rA- obtained in Synthesis Example (I)
I J 2842g St-butyl perbenzoate 2
8g1 polyisocyanate compound (Isonate 1
Impact resistance was evaluated in the same manner as in Example 1, except that the weight was changed to 658 g (43L, manufactured by MO Kasei). The obtained evaluation results are also shown in Table 1.

Example 3 Unsaturated polyester resin rA obtained in Synthesis Example (II)
-II J 2530g, hydroxyl number 187m
gKOH/g polyethylene glycol 282gXt-
Butyl perbenzoate 25g 1 polyisocyanate compound (Is.

impact resistance was evaluated in the same manner as in Example 1, except that the weight was changed to 689 g.

The obtained evaluation results are also shown in Table 1.

Reference Example 2 Unsaturated polyester resin rA- obtained in Synthesis Example (n)
II” 2859g, t-butyl perbenzoate 2
9g1 polyisocyanate compound (Isonate 1
Impact resistance was evaluated in the same manner as in Example 1, except that the weight was changed to 641 g (43L, manufactured by MO Kasei). The obtained evaluation results are also shown in Table 1.

Comparative Example 1 Unsaturated polyester resin obtained in Comparative Synthesis Example (1)
Impact resistance was evaluated in the same manner as in Example 1 except that 3,500 g of BJ, 105 g of zinc stearate, 70 g of magnesium oxide, and 35 g of t-butyl perbenzoate were used.The glass content was changed to 60% by weight. The obtained evaluation results are also shown in Table 1.

Claims (1)

[Scope of Claims] Consists of unsaturated polyester (A), polyhydric alcohol (B), polyisocyanate compound (C), polymerizable vinyl monomer (D) and fiber (E) as main components, ( 1) (A) is an unsaturated dicarboxylic acid or an acid anhydride containing a dicarboxylic acid or anhydride thereof containing 40 to 100 mol% and a polyhydric alcohol having a primary hydroxyl group, and has a hydroxyl value of 115 to 210 m.
gKOH/g and is an unsaturated polyester with an acid value of 5 mgKOH/g or less. (2) (C) has a terminal group of (3) (B) is a liquid polyisocyanate compound having at least two hydroxyl groups in the molecule and having a hydroxyl value of 35 to 1100 mg KO.
H/g polyhydric alcohol, and the following conditions (i), (ii), (iii) and (i)
v) (i) (B) is 5 for the total amount of (A) and (B)
0% by weight or less; (ii) the total amount of (A) and (B) is (A), (B) and (
D) in the range of 50 to 85% by weight based on the total amount of (iii)
) The isocyanate group of (C) is 0.75 to 1.2 times the mole of the hydroxyl group of (A) and (B), (iv) (E) is (A) (C) (D) (E) and (B
) A fiber-reinforced unsaturated polyester resin composition having improved moldability and impact resistance, characterized in that it satisfies the following in an amount of 50 to 70% by weight based on the total amount of: