JPH0733468B2 - Low shrinkage agent for unsaturated polyester resin - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a shrinkage reducing agent for unsaturated polyester resins.

(Prior Art) An unsaturated polyester resin composition has a high dimensional shrinkage ratio upon curing (for example, 10%). Therefore, a molded product obtained from the resin by mold molding, injection molding, etc., may have distortions, cracks, and sink marks. Etc., the lack of smoothness on the surface of the molded product, and the embossing of the reinforcing fibers used for molding.

In order to eliminate these drawbacks, various studies have been conducted in recent years, and, for example, as shown in the invention disclosed in JP-A-48-34289, unsaturated polyester resin has polystyrene,
By mixing and curing an anti-shrinkage thermoplastic polymer such as polymethylmethacrylate, it is possible to produce a molded article having substantially no cure shrinkage, and the above-mentioned drawbacks are considerably improved. Has become.

(Problems to be Solved by the Invention) However, ordinary polystyrene, polymethylmethacrylate, and other anti-shrinkage thermoplastic polymers have low dispersion stability in the unsaturated polyester resin composition, and therefore the mixing for a while (1 When left to stand for up to 5 hours), there is a drawback that the polymer floats on the upper part of the composition, and that it has poor compatibility with fillers and other inorganic fillers and poor dispersibility.

As a solution to these drawbacks, a shrinkage reducing agent composed of a lactone polymer having various terminal groups has been proposed.

However, lactone polymers with high crystallinity have poor solubility in the styrene monomer used at the same time when they are used as a shrinking agent, and when a black molded product is made using carbon black as a pigment, the surface of the molded product is It had the drawback of bleaching.

As a result of diligent study by the present inventors to improve this drawback,
A hydroxy group of a lactone polymer obtained by reacting an ester compound consisting of an oxycarboxylic acid of a fatty acid, a polyhydric alcohol and an aromatic polybasic acid or an anhydride thereof with ε-caprolactone is reacted with the aromatic polybasic group. Solubility in styrene is improved by changing to a polymer blocked with acid anhydride, and when this polymer is added as a low-shrinking agent when making a black molded product using carbon black as a pigment, whitening phenomenon occurs. It was found that, in addition to the fact that a molded part having a small amount of resin can be obtained, a good molded product with almost no shrinkage can be formed, and the present invention was completed.

(Structure of the Invention) That is, the present invention includes "a) 50 to 90% by weight of an aliphatic oxycarboxylic acid b) 10 to 50% by weight of an ester of a polyhydric alcohol and an aromatic polybasic acid or an anhydride thereof c) The above Aromatic polybasic acid anhydrides are used for the hydroxyl groups in the lactone polymer having 90 to 60% by weight of ε-caprolactone with respect to the total amount of a) and b) of 10 to 40% by weight. It is a low-contraction agent for unsaturated polyester resins characterized by comprising a blocked polymer.

As the aliphatic oxycarboxylic acid which is the component a) used in the present invention, glycolic acid, oxycaproic acid, 12-bidoxystearic acid and hydroxypivalic acid are preferable,
Further, oxycarboxylic acid described in the present invention includes -OH, -COO.
It also includes an aliphatic polybasic acid of an aliphatic polyhydric alcohol or a monoester of an anhydride thereof, which has a structure having one H each.

The aliphatic polyhydric alcohol in this case is ethylene glycol, diethylene glycol, 1,3 propanediol, 1,4
-Butylene diol, 1,5 pentane diol, 1,6 hexane diol, 1,2 propylene glycol, 1,3-butylene glycol, neopentyl glycol, hydroxypentipalic acid ester of neopentyl glycol, 2-methyl-1, It is possible to use 3 propanediol, 2,3,5-trimethylpentanediol, trimethylolpropane, trimethylolethane and the like.

Examples of the aliphatic polybasic acid or its anhydride include succinic acid,
There are maleic acid, fumaric acid, odipic acid, sebacic acid, ozelaic acid, dotecanic diacid, succinic anhydride, maleic anhydride and the like, and these can be used together.

The polyhydric alcohol used in the ester of the polyhydric alcohol and the aromatic polybasic acid or its acid anhydride as the component b) of the present invention are ethylene glycol, diethylene glycol, 1,3 propanediol and 1,4-butylene. Diol, 1,
5 pentanediol, 1,6 hexanediol, 1,2 propylene glycol, 1,3-butylene glycol, neopentyl glycol, hydroxypentipalic acid ester of neopentyl glycol, 2-methyl-1,3 propanediol, 2,3 It is possible to use 5,5-trimethylpentanediol, trimethylolpropane, trimethylolethane and the like.

As the aromatic polybasic acid or its anhydride, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid or various anhydrides can be used.

[Epsilon] -caprolactone, which is the component c) of the present invention, is industrially produced and commercially available by oxidizing cyclohexanone with a peracid such as hydrogen peroxide or peracetic acid by the Bayer-Billiker reaction.

In the present invention, it is necessary that 60-90% by weight of ε-caprolactone is contained in the resin as the shrinkage reducing agent.

If it is less than 60% by weight with ε-caprolactone, curing as a low-contracting agent is not exhibited, and if it is more than 90% by weight, the compatibility with styrene becomes poor due to the crystallinity of polycaprolactone.

The charging ratio of the ester of oxycarboxylic acid / polyhydric alcohol and aromatic polybasic acid or anhydride thereof is 5/5 to 9: the ester of oxycarboxylic acid / polyhydric alcohol and aromatic polybasic acid or anhydride thereof. It must be / 1 (weight ratio).

The charging ratio of the ester of oxycarboxylic acid / polyhydric alcohol and aromatic polybasic acid or its anhydride is 50% or less of the ester of polyhydric alcohol and aromatic polybasic acid or its anhydride with respect to oxycarboxylic acid. Does not exhibit the effect as a shrinkage reducing agent, and when it exceeds 90%, whitening phenomenon occurs when carbon black is used as a pigment to make a black product, which impairs commercial properties.

Here, the synthesis of the ester of polyhydric alcohol and aromatic polybasic acid or its anhydride is performed as follows. 0.8-1.2% phthalic anhydride for diethylene glycol
12 times when the reaction temperature was raised by charging a double volume reaction flask.
Phthalic anhydride, which was flaky at 0 to 130 ℃, and diethylene glycol melt and the reaction begins. The reaction temperature is further slowly raised to 150-170 ° C. over 2-3 hours.

Sudden heating may cause the reaction temperature to exceed 200 ° C due to the heat of reaction of phthalic anhydride, which is not preferable because it causes coloration of the product. The reaction temperature is maintained at 150 to 170 ° C and the reaction is continued for 4 to 6 hours.

At the end of the reaction, the concentration of diethylene glycol in the reaction solution is measured using a gas chromatograph, and the remaining amount is quantified to terminate the reaction when the concentration of diethylene glycol is in the range of 17 to 32%.

If the concentration of diethylene glycol is lower than 21%, the esterification reaction will proceed too much and dehydration will start.

Further, if it exceeds 24%, unreacted phthalic anhydride remains, which is not preferable.

In the present invention, oxycaproic acid, which is a ring-opened product thereof, can be used instead of ε-caprolactone which is the component c).

Also, other lactones can be copolymerized.

Next, a method for synthesizing the lactone polymer which is the shrinkage reducing agent of the present invention will be described.

The most basic method is to first synthesize a polyhydric alcohol and an aromatic polybasic acid to prepare a monoester or polyester polyol which is a component b) of a terminal hydroxyl group or a terminal carboxylic acid, and then add an aliphatic oxy group a) as a component. carboxylic acid,
A predetermined amount of ε-caprolactone which is the component c) is charged and ring-opening polymerization is performed to synthesize a lactone polymer.

Further, it can be synthesized by simultaneously charging and reacting oxycarboxylic acid, polyhydric alcohol, aromatic polybasic acid anhydride and ε-caprolactone.

The reaction temperature is 130 to 240 ° C, preferably 140 to 230 ° C.

In addition, passing an inert gas during the reaction gives good results on the hue of the resin.

In this reaction, titanium compounds such as tetrabutyl titanate and tetrapropyl titanate as a caprolactone ring-opening reaction catalyst, dibutyltin laurate, tin octylate, dibutyltin oxide, stannous stannate, and bromide
0.01 to 50 ppm of tin, stannous iodide, etc., especially 0.1 to 10 pp
It is preferable to use m.

Further, among these catalysts, particularly titanium compounds show sufficient catalytic activity for transesterification reaction.

The average molecular weight of the lactone polymer thus obtained is
It is 1000 to 10000.

The structural formula of this polymer is as follows.

_{HO - [- (CH 2)} 5 -COOH] n-CH 2 CH 2 -O- -CH 2 CH 2 [-OCO- (CH 2) 5 -] m-OH (m + n is the number of moles of the lactone) that is, It is a compound having a structure in which a lactone chain having -OH is bound to both ends of a diethylene glycol unit.

If it is less than 1000, the effect as a low-contracting agent is not sufficient, and if it is more than 10,000, the viscosity is high, which is disadvantageous when it is mixed with a curable resin.

Then, an aromatic polybasic acid anhydride is added to the compound having the above structure to block the hydroxyl groups at both ends with benzene rings.

The structural formula of this polymer is as follows.

Phthalic anhydride is a typical aromatic polybasic acid anhydride used for blocking the hydroxyl groups at both ends with benzene rings.

The amount of the aromatic polybasic acid anhydride used is an amount corresponding to the amount of the hydroxyl groups of the compound having hydroxyl groups at both ends.

The reaction temperature is 150 to 200 ° C., and the reaction time is 5 to 10 hours.

The molecular weight can be adjusted by adjusting the reaction molar ratio between the polyester polyol synthesized from the components a) and b) and ε-caprolactone.

The shrinkage reducing agent of the present invention exerts excellent performance on an unsaturated polyester resin, but the unsaturated polyester resin is saturated with α, β-unsaturated dibasic acid and golicol, or if necessary, further saturated. It is produced by using a dibasic acid together.

As the α, β-unsaturated dibasic acid, maleic anhydride, maleic acid, fumaric acid, mesaconic acid, tetraconic acid, itaconic acid, chlorinated maleic acid and the like are used.

Examples of the saturated dibase include orthophthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, halogenated phthalic anhydride, etc., and esters thereof are also used.

As glycols, ethylene glycol, diethylene glycol, propylene glycol, dipropyrin glycol, butylene glycol, neopentyl glycol, hexylene glycol, hydrogenated bisphenol A, 2,
2-di- (4-hydroxypropoxyphenyl) propane, ethylenoxide, propylenoxide and the like are useful.

If the proportion of α, β-unsaturated dibasic acid in the component is less than 50 mol%, the desired low shrinkage effect cannot be sufficiently obtained, and therefore α, β-unsaturated dibasic acid is 50-100. It should be mol%, especially in the case of sheet molding compounds, 100% is better.

For the unsaturated polyester and the production, known production methods such as a dissolution method, a solution method and an epoxy method are used.

Unsaturated polyester has a molecular weight of 1,000 to 3,000 and an acid value of 10 to 5
Those having a hydroxyl value of 0 and a hydroxyl value of 5 to 60 are preferable.

The shrinkage reducing agent of the present invention is usually used by adding an unsaturated monomer having at least one ethylenic double bond in one molecule together with the unsaturated polyester resin.

The unsaturated monomer must be one that can react with the unsaturated polyester to be crosslinked and heat-cured, and one that dissolves the unsaturated polyester is preferable.

Specific unsaturated monomers include, for example, styrene, vinyltoluene, lower alkyl esters of acrylic acid or methacrylic acid (eg, methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, propyl methacrylate, acrylic acid). Propyl, butyl methacrylate, butyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexyl acrylate), methacrylic acid, acrylic acid, divinylbenzene, chlorostyrene, α-methylstyrene, diarylphthalate, ethylene glycol dimethacrylate, trimethylol Propane trimethacrylate, 2.5-dichlorooctylene, 2.5
-Dipromostyrene, pentapromophenol allyl ether, tripromophenyl acrylate, dialkylphosphonic acid, antimontrial alkoxide, diallylbenzenephosphonate, tricresyl phosphate, triallyl phosphate, diallyl ethyl phosphate, β
Examples thereof include methyl- (methylethyl) phosphonoacrylate and (diallylphosphonomethyl) ether, but styrene is mainly used.

Of course, these monomers are not only 1 type, but 2
Mixtures of more than one can also be used.

When the shrinkage-reducing agent of the present invention is used together with the unsaturated polyester resin or the like, an inorganic filler can be usually used together.

Examples of the inorganic filler include metal oxides such as silica, alumina, iron oxide, zinc oxide, and magnesium oxide: aluminum hydroxide, magnesium hydroxide, metal hydroxides such as iron hydroxide: iron powder, aluminum powder, etc. Metal powder: Others such as asbestos powder, glass powder, calcium carbonate, magnesium carbonate, sodium sulfate, diatomaceous earth, etc. (fiber length 3
~ 25m chopped sland and fiberglass mats are excluded).

The particle size is 0.1-100 μm, preferably 30 μm or less.

Further, among these, particularly when a metal hydroxide is used, there is an advantage that the viscosity of the resin composition is low.

When the shrinkage-reducing agent of the present invention is used together with the unsaturated polyester resin or the like, it is usually possible to add an inorganic filler and further use a reinforcing material.

Examples of the reinforcing material include glass fiber, carbon fiber, asbestos, potassium titanate, whiskers and metal fibers.
A fiber having a fiber length of 3 to 25 mm is used.

When the shrinkage reducing agent of the present invention is used together with the unsaturated polyester resin or the like, a polymerization initiator is usually used.

As the polymerization initiator, benzoyl peroxide, lauryl peroxide, methyl ethyl ketone heroxide, dicumyl peroxide, 2.5-di (peroxybenzoate) hexyne-3, tert-butyl perbenzoate and other organic peroxides, Azobizu Azo compounds such as isobutyroonitrile and dimethylazodiisobutyronitrile can be used.

Next, the composition of each component will be described.

30-80 parts by weight of unsaturated polyester and 70-20 parts by weight of ethylenically unsaturated monomer, but unsaturated polyester +
100 parts by weight of the ethylenically unsaturated monomer is used.

When the unsaturated polyester is 30 parts by weight or less, the cured product cannot have practical strength.

On the other hand, if the amount exceeds 80 parts by weight, the viscosity becomes high and handling becomes difficult, and the strength becomes weak.

The lactone polymer in the low-shrinking agent for unsaturated polyester resins of the present invention, which is a low-shrinking agent, is 5 per 100 parts by weight of the total of the unsaturated polyester and the ethylenically unsaturated monomer.
~ 200 parts by weight, preferably 10 to 100 parts by weight.

If it is less than 5 parts by weight, the effect of low shrinkage is insufficient.

If the amount is more than 200 parts by weight, the mechanical strength of the cured product will decrease.

The inorganic filler is 40 to 400 parts by weight, preferably 40 to 400 parts by weight, based on 100 parts by weight of the unsaturated polyester and the ethylenically unsaturated monomer.
It is used in a proportion of 50 to 300 parts by weight.

If it is less than 40 parts by weight, the effect of preventing uneven coloring is not obtained.

Further, if it exceeds 400 parts by weight, the mechanical strength of the obtained cured product is not practical.

The reinforcing material is 10 to 200 parts by weight, preferably 30 to 100 parts by weight based on 100 parts by weight of the unsaturated polyester and the ethylenically unsaturated monomer.
Used at a rate of 100 parts by weight.

If it is 10 parts by weight or less, there is no strengthening hardening, and if it exceeds 200 parts by weight, the strength of the obtained cured product becomes rather low.

A suitable amount of polymerization initiator, generally 0.01 to 0.01 of unsaturated polyester
It is used in an amount of 5% by weight, preferably 0.5-2% by weight.

In addition to these components, silane coupling agents, silane coupling accelerators, aggregation inhibitors, polymerization inhibitors, thickeners,
You may mix | blend a pigment, a lubricant, etc.

To prepare the resin composition of the present invention, a commercially available polyester resin containing an unsaturated polyester and an ethylenically unsaturated monomer is mixed with a lactone polymer, an inorganic filler, a reinforcing material and a polymerization initiator at the same time. May be.

(Effects of the Invention) (a) The novel lactone polymer, which is the low-shrinking agent for unsaturated polyester resin of the present invention, is a low-shrinking agent for unsaturated polyester or epoxy resin, a surface modifier, or a thermoplastic resin. The plasticizer, the pigment dispersant, the urethane pigment dispersibility improver, the paint flexibility imparting agent, the pigment dispersant and the like can be used extremely advantageously in many fields.

(B) The unsaturated polyester resin composition containing the shrinkage-reducing agent for unsaturated polyester resin of the present invention thus prepared is excellent in storage stability and has a shrinkage rate of +0.05.
When about + 0.1% (expansion), there is no unevenness in coloring and a smooth cured product can be provided.

Next, the present invention will be described with reference to synthesis examples and examples.
The present invention is not limited to these.

In the examples, all parts are parts by weight.

Synthesis Example 1 A four-necked flask equipped with a nitrogen inlet tube, a thermometer, a condenser for removing esterified water and a stirrer was charged with 530 parts of diethylene glycol and 740 parts of phthalic anhydride at 140 ° C to 1 ° C.
Reaction at 60 ℃ for 3 hours Acid value 178KHO mg / g, Hydroxyl value 144KO
A polyester polyol of H mg / g (the unit is omitted below) was obtained.

Synthesis Example 2 554 parts of the polyester polyol obtained in Synthesis Example 1, 830 parts of 12-hydroxystearic acid, ε-caprolactone 7840
Parts and 0.01 parts of tetrabutyl titanate were charged in the same apparatus as in Synthesis Example 1 and reacted at 180 ° C. for 7 hours, and then 193 parts of phthalic anhydride was added and reacted at 180 ° C. for 7 hours to give an acid value of 24.2. A lactone polymer having a hydroxyl value of 1 or less and a melting point of 46 to 47 ° C. was obtained.

Synthesis Example 3 Diethylene glycol 197.2 was placed in the same apparatus as in Synthesis Example 1.
Parts, phthalic anhydride 275.3 parts, 12-vidroxystearic acid 1102.5 parts, ε-caprolactone 8925 parts, tetrabutyl titanate 0.1 parts, and after reacting at 180 ° C. for 7 hours, phthalic anhydride 275 parts was further added, By reacting at 180 ° C. for 7 hours, a lactone polymer having an oxide of 25.4, a hydroxyl value of 1 or less, and a melting point of 46 to 47 was obtained.

Example 1 55 parts of unsaturated polyester resin obtained from maleic anhydride and 1.2-propylene glycol, 45 parts of styrene,
After kneading 50 parts of the resin obtained in Synthesis Example-2, 1 part of t-butyl perbenzoate, 1 part of Mgo, 120 parts of calcium carbonate, 2 parts of carbon black as a pigment, and 80 parts of glass fiber having a fiber length of 1 cm with a kneader, 40 The mixture was aged at ℃ for 1 day to obtain a bulk molding compound.

This was injection-molded at 150 ° C. and a pressure of 100 kg / cm ² for 3 minutes to obtain a molded product having a uniform surface.

Molding shrinkage is 0.15 (%) of expansion Surface gloss 60% reflectance
80 to 90%, good results were obtained for hue black.

Example 2 Unsaturated polyester resin 60 similar to that used in Example 1
Parts, styrene 40 parts, resin 30 obtained in Synthesis Example-3, t-butyl perhenzoate 1 part, aluminum hydroxide 100
Parts, 1 part of Mgo, 3 parts of zinc stearate, and 2 parts of carbon black were kneaded with 80 parts of 1 cm long glass fiber with a kneader, and then aged at 40 ° C. for 1 day to obtain a bulk molding compound.

When this was transfer-molded at 150 ° C. and a pressure of 100 kg / cm ² for 3 minutes, a molded product having a uniform surface was obtained.

Molding shrinkage is expansion 0.11 (%) Surface gloss 60 degrees Reflectivity 80 ~
90%, good result of hue black was obtained.

Comparative Example The same procedure as in Example was repeated except that the reaction for blocking the terminal hydroxyl group with phthalic anhydride in Synthesis Example 2 in Example was not carried out, and the obtained molded product was measured by visual inspection and compared with the following table. And showed it.

The reaction was terminated by confirming that the residual amount of ε-caprolactone monomer was 0.5% or less by gas chromatography.

The terminal hydroxyl groups were confirmed to be blocked by chemical analysis (JIS K-1557: phthalic anhydride-pyridine method) to determine the hydroxyl value, and the value was 1 KOH mg / g or less.

Claims (1)

[Claims] 1. A) aliphatic oxycarboxylic acid 50 to 90% by weight b) ester of a polyhydric alcohol with an aromatic polybasic acid or its anhydride 10 to 50% by weight c) of a) and b) above Consists of 90-60% by weight of ε-caprolactone with respect to the total amount of 10-40% by weight, and a polymer in which the hydroxyl group in the lactone polymer having an average molecular weight of 1,000-10,000 is blocked with an aromatic polybasic acid anhydride. A low-contracting agent for unsaturated polyester resins, which is characterized in that