JPH0670174B2 - Impact and shrinkage modifiers for thermosetting polyesters consisting of polyurethane oligomers - Google Patents

Description

The present invention relates to thermosetting polyester resin compositions, and in particular to thermosetting polyester resin compositions containing polyurethane oligomers selected to improve impact resistance and surface properties.

In recent years, there has been a steady increase in the use of reinforced plastic materials for exterior components of automobile structures. In addition, as automobile manufacturers continue to strive for the purpose of reducing vehicle weight, increased plastics usage can be expected.

Glass fiber reinforced thermosetting polyester resins have been widely used in the field of hard plastic automotive parts.
This is due to its generally superior physical properties, such as dimensional stability,
It is largely due to its strength, high temperature resistance and coatability. Other advantages are ease of handling and processability. However, these polyester systems have drawbacks such as brittleness leading to severe impact and fatigue problems. There is also a need for improved surface properties and shrinkage control.

In order to solve these problems, various additives were introduced into polyester sheet molding compound (SMC) and bulk molding compound (BMC). For example, 1977 April
U.S. Pat. No. 4,034 granted to Aubrey South, Jr. on March 26
In 20,036, a liquid polymer such as polybutadiene is added to strengthen the polyester product. However, since these materials are essentially immiscible with the polyester, they cannot be added to it until the resin is mixed with the fiberglass. Saturated diacids or long chain glycols have also been used to prepare polyester resins. The resulting product was flexible, but at the expense of mechanical and thermal properties.

Other work consists of introducing urethane systems into polyester resins. Francis Gowland Hu December 13, 1977
In U.S. Pat.No. 4,062,826 to tchinson et al., a cross-linked polyurethane precursor is polymerized in a mixture of ethylenically unsaturated polyester and vinyl monomer to form a cross-linked structure in the polyester. A product having a mesh of polyurethane gels entangled with each other is obtained.
Although it is reported that higher impact properties are obtained, the fine surface finish required for automobile parts has not been achieved. Strengthening G.Forger SMC ["Plastics World" page 6
3 (June 1978)].

Therefore, there is a great need in the art for improved additives for polyester resin systems that provide high impact and low shrinkage properties.

It has now been found, in accordance with the present invention, that these needs are met by incorporating selected polyurethane oligomer systems into conventional thermosetting polyester resin formulations. In the practice of the present invention, molded plastic products are produced which are characterized by retaining sufficient surface properties due to increased impact properties and low shrinkage.

The polyurethane chemistry system employed by the present invention is formed by the reaction of an organic polyisocyanate and a polyol. In general, the controlled molecular weight oligomers obtained are readily miscible with the polyester resin, so that there is no storage problem due to the immiscibility of the premix. When the polyurethane oligomer-polyester resin system is treated, molded and the molded article cured, the oligomers phase separate to form discrete pockets or centers in the thermoset polyester matrix. The inclusion of flexible polyurethane oligomers significantly improves impact properties. In addition, the unique behavior of the oligomer during curing of the polyester is to ease strain and prevent shrinkage and consequent surface defects.

The polyurethane oligomers used according to the invention have organic polyisocyanates with an NCO / OH equivalent ratio of about 0.3 / 1 to 0.9.
It is prepared by reacting with a polyol by a conventional method so that it becomes 9/1. The NCO / OH ratio is preferably in the range of 0.60 / 1 to 0.99 / 1.

Any suitable organic polyisocyanate or mixture of polyisocyanates can be used to form the polyurethane oligomers, such as 80:20 and 65:35 mixtures of 2,4- and 2,6-isomers. Such as toluene diisocyanate, ethylene diisocyanate, propylene diisocyanate, methylene-bis (4-phenylisocyanate), methylene-bis (4-cyclohexyl) isocyanate, xylene diisocyanate, 3,
Polymeric isocyanates such as 3'-bitluene-4,4'-diisocyanate, hexamethylene diisocyanate, naphthalene-1,5-diisocyanate, isophorone diisocyanate, polyphenylene polymethylene isocyanate, and the like, and mixtures thereof. In a particularly preferred embodiment of the invention, the weight ratio of 2,4-isomer to 2,6-isomer is about 60:40 to 90:10, particularly preferably about 65:35.
A mixture of isomers of 2,4- and 2,6-toluene diisocyanate that is ~ 80: 20 is used.

Polyol reactants used to form polyurethane oligomers include polyester polyols, polyether polyols and mixtures of two or more of these compounds.
The polyol or polyol mixture should have an average molecular weight of 1,000 or more. Average molecular weight is 1,500 ~
6,500 is preferable, and 2,000-4,000 is more preferable. The average functionality of the polyol or polyol blend is usually about 1.5-6.0, preferably about 2-4, and more preferably about 2-3.

Polyester polyol is an essential polyol reactant. Any suitable polyester polyol can be used, including those derived from caprolactone and the products obtained by reacting polycarboxylic acids with polyhydric alcohols by known methods. Representative polycarboxylic acids include, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, phthalic acid and isophthalic acid, mixtures thereof, and the like. . A typical polyhydric alcohol is
Ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, butylene glycol, butanediol, pentanediol, glycerin, trimethylolpropane, trimethylolhexane, hexane 1,2,6-triol, pentaerythritol, It includes various diols such as methyl glucosides, sorbitol, mixtures thereof and the like, triols, tetrols and higher functional alcohols. The preferred polyester polyol is the reaction product of a polycarboxylic acid and a polyhydric alcohol.

Also, any suitable polyether polyol can be used, such as various polyoxyalkylene polyols and mixtures thereof, and the alkylene oxide or the mixture of alkylene oxides is subjected to random or stepwise addition reaction by a known method. Then, it can be prepared by condensation with a polyvalent reaction initiator or a mixture of polyvalent reaction initiators. Representative alkylene oxides include, for example, ethylene oxide, propylene oxide, ptyrene oxide, amylene oxide, etorahydrofuran, and aralkylene oxides such as styrene oxide and halogenated alkylene oxides such as trichlorobutylene oxide. . The most preferred alkylene oxide is propylene oxide or a mixture thereof with ethylene oxide using random or stepwise oxyalkylation.

The polyhydric initiators used to prepare the polyether polyol reactants include the following compounds and mixtures thereof: (a) ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, Aliphatic diols such as butylene glycol, butanediol, pentanediol and the like;
(B) Aliphatic triols such as glycerin, trimethylolpropane, trimethylolpropane, trimethylolhexane and the like; (c) Polyfunctional alcohols such as pentaerythritol, methylglycoside, sorbitol and the like; (d) And polyamines such as tetraethylenediamine and the like; and (e) alkanolamines such as diethanolamine, triethanolamine, and the like. A preferred group of polyhydric initiators used to prepare polyether polyol reactants are aliphatic diols and triols such as ethylene glycol, 1,2-propylene glycol, dipropylene glycol, glycerin, trimethylolpropane and the like. Is included.

The alkylene oxide-multivalent initiator condensation reaction is preferably conducted in the presence of a catalyst such as KOH, which is well known in the art. To carry out this reaction, 1,000 to 10,000, preferably 1,500, using a sufficient proportion of alkylene oxide.
It gives a final polyol product having an average molecular weight of ˜6,500, more preferably 2,000 to 4,000. Thereafter, the catalyst is removed, leaving a polyether polyol suitable for preparing polyurethane oligomers for use in the present invention.

This reaction is preferably carried out in the presence of a polymerizable solvent.
Suitable polymerizable solvents include styrene, substituted styrenes (eg, α-methylstyrene, chlorostyrene, etc.), vinyltoluene, divinylbenzene, esters of acrylic acid and methacrylic acid (eg, methyl methacrylate), which are well known to those skilled in the art. , Butyl acrylate, etc.), acrylic esters (eg diallyl phthalate, diallyl fumarate, etc.) and the like vinyl compounds. The amount of polymerizable solvent used can be varied over a wide range. However, the polymerizable solvent is generally used in an amount of about 0 to 90 parts by weight, preferably about 40 to 70 parts by weight, based on 100 parts by weight of the polyurethane oligomer + polymerizable solvent.

Conventional urethane catalysts such as tertiary amines and metal compounds such as stannas octoate, dibutyltin dilaurate or dibutyldi (laurylmercapto) tin may be used to accelerate the reaction. Other raw materials, such as chain growth agents well known in the polyurethane art, may also be included in the reaction mixture when forming the polyurethane oligomer. These chain growth agents include low molecular weight glycols such as ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, butadiol, hexanediol and the like. Both the reaction temperature and the time depend on many factors and depend, for example, on the exact reactants used. Generally, the reaction temperature is about 20-110.
The reaction time at 0.5 ° C. is preferably about 0.5 to 4.0 hours.

The above polyurethane oligomer is added to the thermosetting polyester resin formulation. These polyester resins include common polyesters and hybrid polyesters such as vinyl esters. Additives that modify the oligomer can be used in effective amounts. The oligomer is preferably added in a proportion of 4 to 42 parts by weight per 100 parts by weight of polyester resin + polymerizable solvent. Most preferred is 12 to 35 parts by weight of oligomer per 100 parts by weight of polyester resin + polymerizable solvent.

Thermoset polyester resins are generally prepared by reacting an unsaturated acid or anhydride or mixture thereof with a polyhydric alcohol or mixture thereof using methods and reagents well known to those skilled in the polyester art. For example, “Encyclopedia of Chem” edited by Kirk-Othmer.
ical Technology "Third Edition, Volume 18, pp. 575-580 (198
See 2), the entire disclosure of which is incorporated herein. Representative reagents include maleic acid, fumaric acid, aconitic acid, mesaconic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, mixtures and the like thereof and ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, Propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, cyclohexanedimethanol, 2,2,4-trimethylpentanediol, bisphenol A, trimethylolethane, Includes trimethylolpropane, dicyclopentadiene glycol, dibromoneopentyl glycol, mixtures thereof and the like. In some cases, the polyester resin may further contain other compounds as co-condensation units, such as dibasic aromatic acids and anhydrides and saturated aliphatic dibasic acids that act as modifiers. Typical examples of such compounds include phthalic anhydride, isophthalic acid, adipic acid, succinic acid, azelaic acid, sebacic acid, etc. and terephthalic acid, various halogenated phthalic anhydride derivatives, trimellitic anhydride, cyclohexane-dicarboxylic acid. Examples thereof include acids and chlorendic acid, and anhydrides of tetrabromophthalic acid and tetrachlorophthalic acid.

Polyurethane oligomer-containing polyester resin systems polymerize and cure in the presence of a thermally activated catalyst for producing free radicals. The actual cure conditions can vary over a wide range, but will depend on the nature and amount of the particular catalyst generally used. Suitable free radical generating catalysts include peroxide or azo type compounds well known to those skilled in the art. Representative peroxide catalysts are benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, lauryl peroxide, cyclohexanone peroxide, t-butyl perbenzoate, t-butyl peroxide.
Butyl hydroperoxide, t-butylbenzene hydroperoxide, cumene hydroperoxide, t-
Organic peroxides and hydroperoxides such as butyl peroctoate and the like. Typical azo compounds are azobis-isobutyronitrile, 2-t
-Butylazo-2-cyano-4-methylpentane and 4-t-butylazo-4-cyanovaleric acid. The preferred catalyst is a peroxide catalyst. Particularly preferred peroxides are t-butyl peroctoate, t-butyl perbenzoate and mixtures thereof. The amount of catalyst may be arbitrary, but is generally about 0.1 to 100 parts by weight per 100 parts by weight of polyester resin, polyurethane oligomer and polymerizable solvent.
Used in an amount of 10 parts by weight.

The composition of the present invention also includes a reinforcing material. Any suitable reinforcing material can be used, such as, for example, chow glass fiber,
Carbon fibers, asbestos fibers, boron nitride whiskers and the like are used. The amount of reinforcing material added to the formulation can be varied over a wide range. A typical prescription is
About 20 to 400 parts by weight, preferably 50 per 100 parts by weight of the polyester resin, polyurethane oligomer and polymerizable solvent.
Generally, up to 200 parts by weight are included.

The composition preferably also includes a filler. Any material known to be suitable as a filler can be used. Generally, a variety of materials can be used, such as CaCO ₃ , clay, alumina, talc, finely divided solids including glass microspheres and the like. Generally, the amount of filler included in the formulation may also vary considerably, but is usually about 50 to 500, preferably 80 to about 100 to 100 parts by weight of polyester resin, polyurethane oligomer and polymerizable solvent.
It is preferably 250 parts by weight.

If desired, other low shrinkage or impact modifying additives can also be included. In a preferred embodiment, the composition also contains a low shrinkage additive of the type described in detail in the pending US patent application with application number 499,656, filed May 31,1983. The entire disclosure of this US application is incorporated by reference herein. Generally, low shrink additives are organic polyisocyanates and 1,00
Consisting of reacting with a polyol having an average molecular weight of 0 or more, the reactant having an NCO / OH equivalent ratio of 0.3 / 1 to 0.99 /
It is generated by using it so that it is in the range of 1. The resulting sub-hydroxyl prepolymer then gives the final free
It is reacted with an anhydride derived from a dicarboxylic acid in a proportion such that a reaction product having an OH content of about 0-5% and an acid number of about 0.1-35 is obtained. Particularly preferred low shrink additives are derived from toluene diisocyanate, polyester polyols and maleic anhydride.

The composition may also optionally include other internal release agents such as other standard ingredients such as calcium stearate, zinc, magnesium or sodium. In the thermosetting polyester technology, pigments, dyes, stabilizers, thixotropes, wetting agents, viscosity modifiers (eg oxides and hydroxides of Group II metals such as magnesium oxide) and various well known to those skilled in the art. Other additives can also be added.

The following examples are intended to further illustrate the present invention, where all parts and percentages are by weight unless otherwise indicated.

Preparation of Polyurethane Oligomer Example 1 200 gallons of agitator equipped with stirrer, thermometer and addition funnel.
Polyester polyol in the reactor 430 pounds (0.27
Amount) and a second polyester polyol 22.65 pon
(0.021 equivalents) and then t-butylcateco
720 lbs of styrene containing 50 ppm of methanol was added. Inside the reactor
Mix the contents thoroughly and add 0.35 lbs of parabenzoquinone.
I got it. The reaction contents are mixed for 15 minutes and the diisocyanate is mixed.
22.5 pounds (0.259 equivalents) were added. 20 reactor contents
After mixing for a minute, the catalyst Added 2.4 pounds. Fever is over
After that, heat the reaction mixture to 158-167 ° F and let the temperature
Was held within that range for 30 minutes. The reaction is infrared
When all of the isocyanate has reacted,
The product was cooled down to room temperature. The substance obtained is transparent
Showed a viscosity of 1,400 cps at 25 ℃ (Brookfield Mode
l “RVT”, Spindle No.3,20rpmf).

Note: This is a diethylene glycol adipate with a molecular weight of about 3,000 and a hydroxyl number of about 35. “Ruco
Ruc sold under the trade name flex S-1011-33 "
o Commercial product of Polymer Corporation.

It is a diethylene glycol adipate derived from glycerin and diethylene glycol and having a molecular weight of about 3,000 and a hydroxyl number of about 52. "Rucoflex
Ruco Polyme sold under the trade name of F-203 "
Commercial product of r Corporation.

This is a mixture of toluene diisocyanate isomers (80:20 mixture of 2,4 / 2,6-isomers).

This is dibutyldi (laurylmercapto) tin,
Witco marketed under the trade name "Fomrez UL-1"
Commercial product of Chemical Corporation.

Gardner scale has a color reading of 5
It was.

Preparation of Thermosetting Polyester Resin Composition Example 2 A thermosetting polyester resin composition containing the polyurethane oligomer prepared in Example 1 was prepared. The formulations used are summarized in Table 1 below.

The "A" and "B" streams were used at a weight ratio of 15.3 / 1. Also, the glass component is composed of 73% of the flow component of “A” and 73% of the flow component of “B” and glass 27 based on the total weight of the formulation.
% Was added.

This formulation was run on an SMC machine having a width of 48 inches at a yield of 100 lbs / min. The mat weight was 16 ounces per square foot. About 350 pounds of composition was made. The obtained SMC paste has a viscosity of 7,000,000 cp in one day of aging.
s (Brookfield Model “HBT”, spindle TA, 5 rpm).

Preparation of Thermoset Polyester Resin Product Example 3 A set of 6 ″ × 6 ″ fiber reinforced panels was prepared by placing the uncured composition prepared in Example 2 in the mold between the battens of a compression molding machine. Prepared. The pressure in the mold was 1,000 psi. The composition was cured at 300 ° F for 2 minutes.

The panel was easily released without sticking at all. Well
Takoto panels feature excellent surface properties and strength.
Attached. It showed the following properties: Specific gravity 1.92 Barcol hardness  14 Condensation (mils / in) −0.91 Surface relief Yu (minimum wave) [Note] The measured value of ASTM D-2583 indicates the expansion of the panel.

Claims (12)

[Claims] 1. A thermosetting polyester resin composition containing a thermosetting polyester resin, a heat-activated free radical generating catalyst, a polymerizable solvent and a reinforcing material, wherein an organic polyisocyanate and a polyester polyol having an average molecular weight of 1,000 or more are used. Is an NCO / OH equivalent ratio prepared in the range of 0.3 / 1 ~ 0.99 / 1 prepared by reacting a polyurethane oligomer having substantially no isocyanate group at the terminal, which is compatible with the thermosetting polyester resin. The above composition, characterized in that it contains from 4 to 42 parts by weight of 100% by weight of the thermosetting polyester resin plus the polymerizable solvent. 2. The composition according to claim 1, wherein the polymerizable solvent is styrene. 3. A thermosetting polyester resin + polymerizable solvent
A composition according to claim 1 comprising 12 to 35 parts by weight of polyurethane oligomer per 100 parts by weight. 4. The NCO / OH equivalent ratio of the organic polyisocyanate to the polyol is 0.60 / 1 to 0.99.
The composition of claim 1 which is the reaction product of / 1. 5. The composition according to claim 1, wherein the polyester polyol is a reaction product of a polycarboxylic acid and a polyhydric alcohol. 6. The composition of claim 1 in which the polyester polyol has an average molecular weight of 1,500 to 6,500. 7. The composition according to claim 1, wherein the polyester polyol has an average molecular weight of 2,000 to 4,000. 8. A composition according to claim 1, wherein the polyurethane oligomer is prepared by using toluene diisocyanate as the organic polyisocyanate. 9. A polymerizable solvent and a thermosetting polyester resin +
It contains 12 to 35 parts by weight of polyurethane oligomer per 100 parts by weight of the polymerizable solvent, the polyurethane oligomer having toluene diisocyanate having an average molecular weight of 1,500 to 6,500 polyester polyol and NCO / OH equivalent ratio of 0.60 / 1 to 0.99 / 1. The composition according to claim 1, which is prepared by reacting with. 10. The polyester polyol is 2,000 to 4,000.
The composition according to claim 9, which has an average molecular weight of 10 and is a reaction product of a polycarboxylic acid and a polyhydric alcohol. 11. A reinforcing material comprising a filler, and (a) a reinforcing material 50 to 20.
Claim 1 wherein 0 parts by weight and (b) 80 to 250 parts by weight of said filler are used per 100 parts by weight of the polyurethane oligomer.
The composition according to item 0. 12. A thermosetting polyester resin, a heat-activated free radical generating catalyst, a polymerizable solvent, a reinforcing material and 4 to 42 parts by weight of a polyurethane oligomer per 100 parts by weight of the thermosetting polyester resin and the polymerizable solvent. Of a polyurethane oligomer prepared by reacting an organic polyisocyanate with a polyester polyol having an average molecular weight of 1,000 or more at an NCO / OH equivalent ratio of 0.3 / 1 to 0.99 / 1. A thermosetting polyester resin composition comprising a polyurethane oligomer that is not terminally terminated with isocyanate groups, and then heating the composition to a temperature sufficient to activate the catalyst and cure the composition. Method of manufacturing things.